CastCheck v0.3.1 · data through 2026-10-28

Permanent link · station × model × lead day

Boston Logan · GraphCast (GFS init) · lead day 3

KBOS · graphcast_gfs · lead 3

Target day = initialization date + 3 days. This page is a permanent link: the numbers change as history accumulates, the address and the methodology version do not. Scores use the latest model version segment, GRAP_v100, starting 2026-01-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 6 carry a QC flag on the observation.

Station
KBOS
Model
graphcast_gfs
Lead
day 3
Data through
2026-10-28
Updated
Methodology
v0.3.1

Every number for this combination84 rows

All four windows × both initializations × both interpolations × every variable. Rows are grouped by variable and the specification is collapsed into one monospace key (window · init · method) so the eye travels straight to the numbers. Two windows that cover exactly the same days — while the record is shorter than a year, 365d and all are the same set — share one row whose key names both, rather than printing the same numbers twice. The row matching the default view is highlighted. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval on this group's own days, and reads — when it could not be computed (fewer than 28 scored days or fewer than 4 blocks). The ±1 °F interval is a Wilson score interval, not a bootstrap.

Skill divides by the persistence MAE on the days both have a value; that denominator and the size of the intersection are printed under the number, so the score can be checked rather than taken on trust. MAE debiased and skill, debiased remove a bias estimated on the 30 scored days before each day and applied forward — out of sample, never fitted on the day being scored; n debiased is how many days had enough history to qualify. n QC next to n counts days whose observation carries a QC flag.

Every window, initialization, interpolation and variable for KBOS · graphcast_gfs · lead 3.
Window · init · methodnMAE °FMAE debiased °FBias °FRMSE °F±1 °F±2 °F±3 °FSkillSkill, debiased (out-of-sample)Period
instantaneous temperature t2
30d · 00Z · bilinear162.29—1.53−1.53—3.32—31%[14%, 56%]61%78%+0.71—vs 7.34 (n=15)+0.74n=162026-09-30 → 2026-10-25
90d · 00Z · bilinear this view522.63[2.32, 2.94]1.75−1.52[−2.06, −1.00]3.50[3.05, 3.96]24%[14%, 37%]50%66%+0.54[+0.35, +0.66]vs 5.59 (n=49)+0.58n=522026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2031 QC3.37[3.08, 3.70]2.11−1.85[−2.30, −1.41]4.47[4.04, 4.90]20%[15%, 26%]39%55%+0.59[+0.52, +0.64]vs 8.02 (n=191)+0.71n=1882026-01-04 → 2026-10-25
30d · 00Z · nearest162.21—1.57−1.32—3.29—42%[22%, 65%]62%75%+0.72—vs 7.34 (n=15)+0.74n=162026-09-30 → 2026-10-25
90d · 00Z · nearest522.56[2.26, 2.87]1.76−1.35[−1.93, −0.81]3.46[3.01, 3.92]30%[19%, 43%]52%65%+0.55[+0.36, +0.67]vs 5.59 (n=49)+0.58n=522026-08-03 → 2026-10-25
365d · all · 00Z · nearest2031 QC3.31[3.03, 3.63]2.17−1.70[−2.14, −1.25]4.43[4.01, 4.86]22%[17%, 28%]39%56%+0.60[+0.53, +0.65]vs 8.02 (n=191)+0.70n=1882026-01-04 → 2026-10-25
30d · 12Z · bilinear222.41—1.54−1.91—3.27—32%[16%, 53%]48%69%+0.69—vs 7.39 (n=21)+0.77n=222026-09-30 → 2026-10-27
90d · 12Z · bilinear642.60[2.27, 2.97]1.71−1.60[−2.20, −1.03]3.39[2.93, 3.81]28%[18%, 40%]45%67%+0.57[+0.45, +0.67]vs 6.05 (n=60)+0.66n=642026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2361 QC3.21[2.95, 3.48]2.04−1.84[−2.23, −1.41]4.15[3.80, 4.50]22%[17%, 27%]38%55%+0.60[+0.55, +0.65]vs 7.92 (n=225)+0.71n=2212026-01-04 → 2026-10-27
30d · 12Z · nearest222.35—1.60−1.74—3.23—32%[16%, 53%]50%70%+0.69—vs 7.39 (n=21)+0.76n=222026-09-30 → 2026-10-27
90d · 12Z · nearest642.59[2.26, 2.95]1.76−1.47[−2.08, −0.87]3.36[2.93, 3.77]28%[18%, 40%]43%66%+0.57[+0.45, +0.67]vs 6.05 (n=60)+0.65n=642026-07-31 → 2026-10-27
365d · all · 12Z · nearest2361 QC3.17[2.91, 3.43]2.10−1.69[−2.08, −1.26]4.13[3.77, 4.50]22%[17%, 28%]39%56%+0.61[+0.55, +0.65]vs 7.92 (n=225)+0.70n=2212026-01-04 → 2026-10-27
instantaneous temperature, 00Z t2_00z
30d · 00Z · bilinear163.06—2.15−3.00—4.36—25%[10%, 49%]50%62%+0.51—vs 6.25 (n=16)+0.67n=162026-09-30 → 2026-10-25
90d · 00Z · bilinear533.17[2.56, 3.80]2.58−2.75[−3.61, −1.87]4.35[3.45, 5.15]19%[11%, 31%]51%60%+0.43[+0.22, +0.58]vs 5.58 (n=52)+0.54n=532026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2123.86[3.39, 4.35]3.25−2.50[−3.09, −1.82]5.16[4.42, 5.92]18%[13%, 24%]35%50%+0.52[+0.44, +0.59]vs 8.03 (n=211)+0.61n=1972026-01-04 → 2026-10-25
30d · 00Z · nearest162.95—2.13−2.84—4.27—31%[14%, 56%]50%62%+0.53—vs 6.25 (n=16)+0.67n=162026-09-30 → 2026-10-25
90d · 00Z · nearest533.10[2.48, 3.71]2.61−2.62[−3.50, −1.69]4.30[3.37, 5.09]25%[15%, 38%]49%60%+0.44[+0.23, +0.60]vs 5.58 (n=52)+0.54n=532026-08-03 → 2026-10-25
365d · all · 00Z · nearest2123.81[3.34, 4.31]3.28−2.38[−2.97, −1.71]5.11[4.37, 5.87]18%[13%, 24%]36%52%+0.52[+0.45, +0.59]vs 8.03 (n=211)+0.61n=1972026-01-04 → 2026-10-25
30d · 12Z · bilinear233.44—2.62−3.13—4.66—22%[10%, 42%]39%52%+0.54—vs 7.48 (n=23)+0.67n=232026-09-30 → 2026-10-27
90d · 12Z · bilinear673.40[2.62, 4.13]2.96−2.95[−3.87, −2.01]4.55[3.68, 5.31]28%[19%, 40%]43%54%+0.45[+0.26, +0.60]vs 6.29 (n=66)+0.54n=672026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2493.78[3.36, 4.23]3.22−2.63[−3.23, −2.09]4.91[4.34, 5.50]20%[16%, 25%]35%46%+0.53[+0.46, +0.60]vs 8.08 (n=247)+0.62n=2342026-01-04 → 2026-10-27
30d · 12Z · nearest233.32—2.66−3.04—4.62—22%[10%, 42%]39%52%+0.56—vs 7.48 (n=23)+0.66n=232026-09-30 → 2026-10-27
90d · 12Z · nearest673.38[2.62, 4.12]3.01−2.86[−3.79, −1.88]4.53[3.66, 5.32]30%[20%, 42%]42%54%+0.45[+0.26, +0.61]vs 6.29 (n=66)+0.54n=672026-07-31 → 2026-10-27
365d · all · 12Z · nearest2493.76[3.33, 4.25]3.28−2.53[−3.11, −1.99]4.93[4.33, 5.57]21%[17%, 27%]34%48%+0.53[+0.47, +0.60]vs 8.08 (n=247)+0.61n=2342026-01-04 → 2026-10-27
instantaneous temperature, 06Z t2_06z
30d · 00Z · bilinear172.22—1.99−1.38—2.82—24%[10%, 47%]53%76%+0.72—vs 8.01 (n=17)+0.75n=172026-09-30 → 2026-10-28
90d · 00Z · bilinear542.41[2.12, 2.74]2.03−1.66[−2.25, −0.87]2.94[2.58, 3.29]24%[15%, 37%]44%63%+0.54[+0.22, +0.70]vs 5.23 (n=53)+0.60n=542026-08-03 → 2026-10-28
365d · all · 00Z · bilinear2093.22[2.87, 3.59]2.13−2.83[−3.32, −2.35]3.95[3.53, 4.34]18%[14%, 24%]36%51%+0.56[+0.47, +0.64]vs 7.25 (n=202)+0.71n=1942026-01-04 → 2026-10-28
30d · 00Z · nearest172.12—2.08−0.97—2.74—35%[17%, 59%]53%76%+0.73—vs 8.01 (n=17)+0.74n=172026-09-30 → 2026-10-28
90d · 00Z · nearest542.31[2.04, 2.62]2.07−1.37[−1.98, −0.55]2.85[2.51, 3.20]30%[19%, 43%]46%63%+0.56[+0.26, +0.71]vs 5.23 (n=53)+0.59n=542026-08-03 → 2026-10-28
365d · all · 00Z · nearest2093.05[2.71, 3.41]2.15−2.59[−3.07, −2.11]3.80[3.38, 4.19]22%[17%, 28%]35%54%+0.59[+0.50, +0.65]vs 7.25 (n=202)+0.70n=1942026-01-04 → 2026-10-28
30d · 12Z · bilinear242.13—1.82−1.62—2.63—38%[21%, 57%]50%75%+0.65—vs 6.15 (n=24)+0.72n=242026-09-30 → 2026-10-28
90d · 12Z · bilinear662.41[2.00, 2.88]1.91−1.83[−2.50, −1.12]2.93[2.46, 3.39]29%[19%, 41%]41%68%+0.53[+0.32, +0.66]vs 5.15 (n=65)+0.63n=662026-07-31 → 2026-10-28
365d · all · 12Z · bilinear2423.08[2.71, 3.47]2.15−2.66[−3.13, −2.22]3.78[3.38, 4.19]22%[18%, 28%]35%54%+0.57[+0.50, +0.63]vs 7.17 (n=236)+0.70n=2272026-01-04 → 2026-10-28
30d · 12Z · nearest242.04—1.85−1.30—2.51—33%[18%, 53%]54%75%+0.67—vs 6.15 (n=24)+0.71n=242026-09-30 → 2026-10-28
90d · 12Z · nearest662.32[1.95, 2.75]1.91−1.55[−2.24, −0.81]2.79[2.40, 3.20]26%[17%, 37%]42%68%+0.55[+0.35, +0.67]vs 5.15 (n=65)+0.63n=662026-07-31 → 2026-10-28
365d · all · 12Z · nearest2422.93[2.59, 3.31]2.17−2.41[−2.88, −1.97]3.63[3.23, 4.03]21%[17%, 27%]40%59%+0.59[+0.53, +0.65]vs 7.17 (n=236)+0.70n=2272026-01-04 → 2026-10-28
instantaneous temperature, 12Z t2_12z
30d · 00Z · bilinear171.61—1.57−0.77—2.16—41%[22%, 64%]65%94%+0.73—vs 6.02 (n=17)+0.74n=172026-09-30 → 2026-10-28
90d · 00Z · bilinear551.99[1.68, 2.31]1.66−1.06[−1.70, −0.43]2.39[2.01, 2.77]27%[17%, 40%]53%82%+0.55[+0.36, +0.68]vs 4.41 (n=55)+0.63n=552026-08-03 → 2026-10-28
365d · all · 00Z · bilinear2132.95[2.48, 3.46]2.43−1.92[−2.52, −1.38]3.79[3.20, 4.33]24%[19%, 30%]42%61%+0.58[+0.50, +0.65]vs 6.97 (n=211)+0.65n=1982026-01-04 → 2026-10-28
30d · 00Z · nearest171.54—1.61−0.40—2.14—47%[26%, 69%]71%88%+0.74—vs 6.02 (n=17)+0.73n=172026-09-30 → 2026-10-28
90d · 00Z · nearest551.93[1.65, 2.23]1.68−0.80[−1.46, −0.14]2.35[2.02, 2.70]29%[19%, 42%]58%80%+0.56[+0.38, +0.69]vs 4.41 (n=55)+0.62n=552026-08-03 → 2026-10-28
365d · all · 00Z · nearest2132.87[2.42, 3.35]2.46−1.68[−2.27, −1.14]3.70[3.15, 4.23]24%[19%, 30%]44%61%+0.59[+0.51, +0.65]vs 6.97 (n=211)+0.65n=1982026-01-04 → 2026-10-28
30d · 12Z · bilinear241.83—1.72−1.00—2.27—29%[15%, 49%]54%88%+0.69—vs 5.89 (n=24)+0.72n=242026-09-30 → 2026-10-28
90d · 12Z · bilinear682.01[1.70, 2.38]1.79−1.01[−1.61, −0.39]2.44[2.01, 2.91]28%[19%, 40%]51%84%+0.60[+0.50, +0.68]vs 5.02 (n=67)+0.66n=682026-07-31 → 2026-10-28
365d · all · 12Z · bilinear2482.81[2.47, 3.23]2.33−1.74[−2.31, −1.24]3.55[3.13, 4.02]21%[17%, 27%]42%63%+0.60[+0.54, +0.66]vs 6.99 (n=245)+0.67n=2332026-01-04 → 2026-10-28
30d · 12Z · nearest241.81—1.81−0.65—2.26—33%[18%, 53%]62%83%+0.69—vs 5.89 (n=24)+0.70n=242026-09-30 → 2026-10-28
90d · 12Z · nearest682.02[1.70, 2.41]1.86−0.76[−1.41, −0.10]2.44[2.01, 2.90]29%[20%, 41%]51%79%+0.60[+0.50, +0.68]vs 5.02 (n=67)+0.65n=682026-07-31 → 2026-10-28
365d · all · 12Z · nearest2482.74[2.41, 3.11]2.39−1.51[−2.06, −1.01]3.49[3.08, 3.94]23%[18%, 29%]44%63%+0.61[+0.55, +0.67]vs 6.99 (n=245)+0.66n=2332026-01-04 → 2026-10-28
instantaneous temperature, 18Z t2_18z
30d · 00Z · bilinear162.22—2.24−1.03—3.50—38%[18%, 61%]75%81%+0.70—vs 7.79 (n=15)+0.72n=162026-09-30 → 2026-10-25
90d · 00Z · bilinear543.02[2.39, 3.56]3.07−0.84[−1.64, 0.05]3.97[3.27, 4.52]24%[15%, 37%]48%57%+0.56[+0.43, +0.68]vs 6.92 (n=53)+0.56n=542026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2131 QC3.38[2.95, 3.84]3.49−0.03[−0.69, 0.67]4.71[3.98, 5.51]22%[17%, 28%]40%58%+0.65[+0.57, +0.72]vs 9.75 (n=211)+0.65n=1982026-01-04 → 2026-10-25
30d · 00Z · nearest162.17—2.19−1.08—3.52—56%[33%, 77%]75%75%+0.71—vs 7.79 (n=15)+0.72n=162026-09-30 → 2026-10-25
90d · 00Z · nearest542.99[2.34, 3.55]3.05−0.86[−1.67, 0.02]3.98[3.23, 4.54]33%[22%, 47%]50%57%+0.56[+0.43, +0.69]vs 6.92 (n=53)+0.56n=542026-08-03 → 2026-10-25
365d · all · 00Z · nearest2131 QC3.44[3.01, 3.92]3.53−0.02[−0.71, 0.72]4.81[4.07, 5.62]23%[18%, 29%]41%57%+0.65[+0.56, +0.71]vs 9.75 (n=211)+0.64n=1982026-01-04 → 2026-10-25
30d · 12Z · bilinear222.06—1.93−1.58—2.75—36%[20%, 57%]55%68%+0.76—vs 9.08 (n=21)+0.79n=222026-09-30 → 2026-10-27
90d · 12Z · bilinear662.65[2.19, 3.13]2.63−0.76[−1.43, −0.06]3.28[2.72, 3.78]23%[14%, 34%]42%61%+0.65[+0.54, +0.74]vs 7.62 (n=65)+0.66n=662026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2461 QC3.11[2.75, 3.55]3.20−0.17[−0.70, 0.41]4.16[3.58, 4.88]23%[18%, 29%]41%57%+0.67[+0.61, +0.73]vs 9.53 (n=244)+0.67n=2312026-01-04 → 2026-10-27
30d · 12Z · nearest222.09—1.90−1.64—2.78—36%[20%, 57%]50%77%+0.76—vs 9.08 (n=21)+0.79n=222026-09-30 → 2026-10-27
90d · 12Z · nearest662.72[2.28, 3.18]2.67−0.82[−1.48, −0.13]3.33[2.82, 3.81]23%[14%, 34%]38%61%+0.64[+0.53, +0.72]vs 7.62 (n=65)+0.66n=662026-07-31 → 2026-10-27
365d · all · 12Z · nearest2461 QC3.18[2.82, 3.64]3.25−0.17[−0.73, 0.43]4.26[3.68, 5.01]22%[17%, 28%]41%56%+0.67[+0.60, +0.72]vs 9.53 (n=244)+0.67n=2312026-01-04 → 2026-10-27
sampled daily maximum tmax_s
30d · 00Z · bilinear162.21—2.28−1.02—3.48—38%[18%, 61%]75%81%+0.68—vs 7.07 (n=15)+0.69n=162026-09-30 → 2026-10-25
90d · 00Z · bilinear522.77[2.26, 3.32]2.87−1.04[−1.76, −0.33]3.72[3.06, 4.35]27%[17%, 40%]52%62%+0.54[+0.39, +0.67]vs 6.19 (n=49)+0.53n=522026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2033.19[2.83, 3.62]3.36−0.87[−1.48, −0.23]4.23[3.77, 4.71]23%[17%, 29%]42%60%+0.67[+0.59, +0.72]vs 9.26 (n=191)+0.65n=1882026-01-04 → 2026-10-25
30d · 00Z · nearest162.16—2.23−1.07—3.51—56%[33%, 77%]75%75%+0.68—vs 7.07 (n=15)+0.69n=162026-09-30 → 2026-10-25
90d · 00Z · nearest522.73[2.20, 3.31]2.84−1.06[−1.77, −0.38]3.72[3.02, 4.38]35%[23%, 48%]56%62%+0.55[+0.39, +0.68]vs 6.19 (n=49)+0.53n=522026-08-03 → 2026-10-25
365d · all · 00Z · nearest2033.22[2.85, 3.67]3.38−0.84[−1.45, −0.18]4.29[3.80, 4.80]24%[19%, 30%]43%58%+0.66[+0.59, +0.72]vs 9.26 (n=191)+0.65n=1882026-01-04 → 2026-10-25
30d · 12Z · bilinear221.93—1.65−1.71—2.58—32%[16%, 53%]55%77%+0.76—vs 8.35 (n=21)+0.81n=222026-09-30 → 2026-10-27
90d · 12Z · bilinear642.33[1.92, 2.77]2.21−1.04[−1.66, −0.40]2.96[2.41, 3.47]27%[17%, 38%]50%67%+0.66[+0.56, +0.74]vs 7.09 (n=60)+0.68n=642026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2362.92[2.55, 3.32]3.00−0.95[−1.51, −0.34]3.99[3.36, 4.67]26%[21%, 32%]45%59%+0.68[+0.62, +0.73]vs 8.95 (n=225)+0.67n=2212026-01-04 → 2026-10-27
30d · 12Z · nearest221.97—1.64−1.79—2.65—36%[20%, 57%]50%77%+0.75—vs 8.35 (n=21)+0.81n=222026-09-30 → 2026-10-27
90d · 12Z · nearest642.40[2.01, 2.82]2.25−1.11[−1.75, −0.44]3.02[2.50, 3.51]28%[19%, 40%]45%64%+0.65[+0.55, +0.73]vs 7.09 (n=60)+0.67n=642026-07-31 → 2026-10-27
365d · all · 12Z · nearest2362.95[2.58, 3.36]3.01−0.94[−1.52, −0.32]4.04[3.42, 4.71]26%[21%, 32%]44%59%+0.68[+0.61, +0.72]vs 8.95 (n=225)+0.67n=2212026-01-04 → 2026-10-27
sampled daily minimum tmin_s
30d · 00Z · bilinear161.86—1.72−0.94—2.37—31%[14%, 56%]62%88%+0.73—vs 5.87 (n=15)+0.76n=162026-09-30 → 2026-10-25
90d · 00Z · bilinear521.90[1.58, 2.27]1.86−0.98[−1.63, −0.28]2.36[1.92, 2.79]33%[22%, 46%]63%81%+0.56[+0.26, +0.69]vs 3.97 (n=49)+0.55n=522026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2033.14[2.67, 3.62]2.49−2.10[−2.65, −1.52]4.02[3.47, 4.57]22%[17%, 28%]41%58%+0.53[+0.44, +0.60]vs 6.49 (n=191)+0.62n=1882026-01-04 → 2026-10-25
30d · 00Z · nearest161.86—1.81−0.57—2.36—38%[18%, 61%]62%81%+0.73—vs 5.87 (n=15)+0.75n=162026-09-30 → 2026-10-25
90d · 00Z · nearest521.88[1.57, 2.21]1.94−0.70[−1.41, 0.03]2.35[1.91, 2.77]37%[25%, 50%]62%79%+0.56[+0.26, +0.69]vs 3.97 (n=49)+0.53n=522026-08-03 → 2026-10-25
365d · all · 00Z · nearest2033.03[2.57, 3.50]2.53−1.84[−2.39, −1.27]3.93[3.40, 4.46]24%[18%, 30%]42%59%+0.55[+0.46, +0.61]vs 6.49 (n=191)+0.61n=1882026-01-04 → 2026-10-25
30d · 12Z · bilinear221.91—1.76−1.25—2.45—45%[27%, 65%]55%77%+0.71—vs 5.86 (n=21)+0.75n=222026-09-30 → 2026-10-27
90d · 12Z · bilinear641.85[1.44, 2.24]1.79−1.13[−1.70, −0.57]2.37[1.89, 2.78]41%[29%, 53%]58%77%+0.63[+0.48, +0.73]vs 4.73 (n=60)+0.64n=642026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2362.91[2.54, 3.26]2.38−1.91[−2.38, −1.42]3.68[3.23, 4.11]22%[17%, 28%]39%57%+0.57[+0.50, +0.62]vs 6.55 (n=225)+0.64n=2212026-01-04 → 2026-10-27
30d · 12Z · nearest221.83—1.82−0.95—2.37—41%[23%, 61%]59%77%+0.72—vs 5.86 (n=21)+0.74n=222026-09-30 → 2026-10-27
90d · 12Z · nearest641.81[1.46, 2.16]1.82−0.87[−1.47, −0.26]2.30[1.89, 2.67]39%[28%, 51%]58%75%+0.64[+0.49, +0.73]vs 4.73 (n=60)+0.63n=642026-07-31 → 2026-10-27
365d · all · 12Z · nearest2362.80[2.45, 3.13]2.42−1.65[−2.11, −1.14]3.58[3.14, 4.00]24%[19%, 30%]44%60%+0.58[+0.52, +0.64]vs 6.55 (n=225)+0.64n=2212026-01-04 → 2026-10-27

+ model too warm − model too cold bias interval includes zero ★ lowest MAE among ranked models (n ≥ 30) = not distinguishable from the leader ▼ worse than the leader ▲ better than the leader — all three Holm-corrected within this table, over the family of comparisons against the leader; the uncorrected verdict for every pair is published in the pairwise table of each permanent link and in pairwise_latest.csv.gzn < 30 greyed and unranked CI is a 95 % moving-block bootstrap interval on the group's own days, and reads — when it could not be computed skill reads — when fewer than 10 days are common to the model and the baseline: the ratio of two means over a handful of shared days is not a number worth printing

Against the NWS daily extremes (secondary)

This comparison scores four 6-hourly forecast samples against the true daily extreme, so it includes a sampling penalty. The size of that penalty depends on each model's own diurnal amplitude, which is one of the things this site measures, so these numbers are published for operational relevance and are never used for ranking.

Window · init · methodnMAE °FBias °FRMSE °F±1 °F±3 °FPeriod
daily maximum vs NWS CLI tmax_cli
30d · 00Z · bilinear163.07—−2.46—4.4112%[3%, 36%]69%2026-09-30 → 2026-10-25
90d · 00Z · bilinear533.47[2.69, 4.32]−2.67[−3.46, −1.95]4.5825%[15%, 38%]51%2026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2134.10[3.70, 4.56]−2.88[−3.49, −2.16]5.1514%[10%, 19%]45%2026-01-04 → 2026-10-25
30d · 00Z · nearest163.11—−2.51—4.456%[1%, 28%]69%2026-09-30 → 2026-10-25
90d · 00Z · nearest533.49[2.69, 4.35]−2.69[−3.50, −1.92]4.6019%[11%, 31%]53%2026-08-03 → 2026-10-25
365d · all · 00Z · nearest2134.11[3.69, 4.58]−2.86[−3.47, −2.13]5.1712%[8%, 17%]45%2026-01-04 → 2026-10-25
30d · 12Z · bilinear233.59—−3.52—4.339%[2%, 27%]48%2026-09-30 → 2026-10-27
90d · 12Z · bilinear663.74[3.15, 4.28]−3.07[−3.82, −2.23]4.4112%[6%, 22%]42%2026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2484.14[3.74, 4.59]−3.09[−3.71, −2.47]5.1414%[10%, 19%]40%2026-01-04 → 2026-10-27
30d · 12Z · nearest233.67—−3.61—4.439%[2%, 27%]48%2026-09-30 → 2026-10-27
90d · 12Z · nearest663.82[3.25, 4.34]−3.13[−3.88, −2.27]4.4911%[5%, 20%]44%2026-07-31 → 2026-10-27
365d · all · 12Z · nearest2484.17[3.75, 4.61]−3.09[−3.73, −2.45]5.1812%[9%, 17%]41%2026-01-04 → 2026-10-27
daily minimum vs NWS CLI tmin_cli
30d · 00Z · bilinear161.81—+0.75—2.2325%[10%, 49%]88%2026-09-30 → 2026-10-25
90d · 00Z · bilinear531.98[1.56, 2.38]+1.11[0.48, 1.78]2.5232%[21%, 45%]83%2026-08-03 → 2026-10-25
365d · all · 00Z · bilinear2132.60[2.19, 3.03]+0.20[−0.37, 0.73]3.5127%[21%, 33%]70%2026-01-04 → 2026-10-25
30d · 00Z · nearest162.01—+1.12—2.4531%[14%, 56%]81%2026-09-30 → 2026-10-25
90d · 00Z · nearest532.14[1.71, 2.57]+1.39[0.75, 2.08]2.7132%[21%, 45%]79%2026-08-03 → 2026-10-25
365d · all · 00Z · nearest2132.63[2.23, 3.05]+0.47[−0.11, 0.99]3.5527%[21%, 33%]70%2026-01-04 → 2026-10-25
30d · 12Z · bilinear232.09—+0.98—2.5317%[7%, 37%]70%2026-09-30 → 2026-10-27
90d · 12Z · bilinear661.85[1.58, 2.16]+0.88[0.28, 1.45]2.2726%[17%, 37%]80%2026-07-31 → 2026-10-27
365d · all · 12Z · bilinear2482.44[2.10, 2.80]+0.30[−0.24, 0.78]3.2225%[20%, 31%]71%2026-01-04 → 2026-10-27
30d · 12Z · nearest232.25—+1.30—2.7222%[10%, 42%]74%2026-09-30 → 2026-10-27
90d · 12Z · nearest661.99[1.64, 2.36]+1.16[0.54, 1.78]2.4433%[23%, 45%]79%2026-07-31 → 2026-10-27
365d · all · 12Z · nearest2482.48[2.15, 2.85]+0.57[0.04, 1.06]3.2826%[21%, 32%]71%2026-01-04 → 2026-10-27

Daily error, last 90 days

Forecast − observed, °F, 00Z bilinear instantaneous temperature. The dashed line is zero; the thick line is a centred 7-day mean, drawn only where the whole window is present. Gaps are days with no score, never interpolation.

Daily forecast minus observed error in °F for GraphCast (GFS init) at KBOS, lead day 3, 00Z bilinear t2+10+50-5-102026-08-03: +0.23 °F2026-08-06: -1.58 °F2026-08-09: -0.47 °F2026-08-11: -0.34 °F2026-08-12: -6.78 °F2026-08-14: -3.91 °F2026-08-17: -4.29 °F2026-08-18: +0.2 °F2026-08-19: -3.84 °F2026-08-20: -2.34 °F2026-08-21: +2.3 °F2026-08-22: -0.74 °F2026-08-25: -4.45 °F2026-08-27: -2.03 °F2026-08-28: -5.74 °F2026-08-29: +0.12 °F2026-08-30: -2.62 °F2026-09-01: -0.23 °F2026-09-02: -2.96 °F2026-09-03: +3.06 °F2026-09-04: +1.45 °F2026-09-06: +0.83 °F2026-09-08: -3.13 °F2026-09-12: -3 °F2026-09-14: -2.24 °F2026-09-15: -0.37 °F2026-09-16: -4.13 °F2026-09-17: -3.16 °F2026-09-18: -2.26 °F2026-09-19: -1.05 °F2026-09-20: -4.13 °F2026-09-21: -0.08 °F2026-09-22: -1.81 °F2026-09-24: -0.45 °F2026-09-25: -1.75 °F2026-09-26: -0.78 °F2026-09-27: -0.88 °F2026-09-28: +2.05 °F2026-09-30: -0.55 °F2026-10-04: +0.56 °F2026-10-05: -1.65 °F2026-10-06: -1.64 °F2026-10-08: -1.76 °F2026-10-10: -3.33 °F2026-10-12: -5.82 °F2026-10-14: -0.66 °F2026-10-15: -0.26 °F2026-10-16: -3.75 °F2026-10-18: +1.59 °F2026-10-20: -1.1 °F2026-10-21: +1.22 °F2026-10-23: -2.45 °F2026-10-24: -1.04 °F2026-10-25: -3.89 °F2026-10-28: -1.44 °F2026-08-032026-10-28°F, forecast − observed

Source: CastCheck · NWS ASOS routine METAR · CSV of these values. Hover a point for its date and value.

Error distribution

All scored days for 00Z bilinear instantaneous temperature, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides.

Distribution of the signed daily error in °F for GraphCast (GFS init) at KBOS, lead day 3-25 to -22.5 °F: 0 days-22.5 to -20 °F: 0 days-20 to -17.5 °F: 0 days-17.5 to -15 °F: 0 days-15 to -12.5 °F: 2 days-12.5 to -10 °F: 13 days-10 to -7.5 °F: 39 days-7.5 to -5 °F: 100 days-5 to -2.5 °F: 213 days-2.5 to 0 °F: 248 days0 to 2.5 °F: 143 days2.5 to 5 °F: 54 days5 to 7.5 °F: 17 days7.5 to 10 °F: 11 days10 to 12.5 °F: 0 days12.5 to 15 °F: 0 days15 to 17.5 °F: 3 days17.5 to 20 °F: 2 days20 to 22.5 °F: 1 day22.5 to 25 °F: 1 daydashed: P50 |e| 2.74 · P90 |e| 7.12 °F-250+25 °Fn = 847 days

Source: CastCheck · bins are equal width over the plotted range. Hover a bar for its bin and count.

The same series as a table (87 days, newest first) · download CSV
Climatological dayError °F
2026-10-28−1.44
2026-10-27—
2026-10-26—
2026-10-25−3.89
2026-10-24−1.04
2026-10-23−2.45
2026-10-22—
2026-10-21+1.22
2026-10-20−1.10
2026-10-19—
2026-10-18+1.59
2026-10-17—
2026-10-16−3.75
2026-10-15−0.26
2026-10-14−0.66
2026-10-13—
2026-10-12−5.82
2026-10-11—
2026-10-10−3.33
2026-10-09—
2026-10-08−1.76
2026-10-07—
2026-10-06−1.64
2026-10-05−1.65
2026-10-04+0.56
2026-10-03—
2026-10-02—
2026-10-01—
2026-09-30−0.55
2026-09-29—
2026-09-28+2.05
2026-09-27−0.88
2026-09-26−0.78
2026-09-25−1.75
2026-09-24−0.45
2026-09-23—
2026-09-22−1.81
2026-09-21−0.08
2026-09-20−4.13
2026-09-19−1.05
2026-09-18−2.26
2026-09-17−3.16
2026-09-16−4.13
2026-09-15−0.37
2026-09-14−2.24
2026-09-13—
2026-09-12−3.00
2026-09-11—
2026-09-10—
2026-09-09—
2026-09-08−3.13
2026-09-07—
2026-09-06+0.83
2026-09-05—
2026-09-04+1.45
2026-09-03+3.06
2026-09-02−2.96
2026-09-01−0.23
2026-08-31—
2026-08-30−2.62
2026-08-29+0.12
2026-08-28−5.74
2026-08-27−2.03
2026-08-26—
2026-08-25−4.45
2026-08-24—
2026-08-23—
2026-08-22−0.74
2026-08-21+2.30
2026-08-20−2.34
2026-08-19−3.84
2026-08-18+0.20
2026-08-17−4.29
2026-08-16—
2026-08-15—
2026-08-14−3.91
2026-08-13—
2026-08-12−6.78
2026-08-11−0.34
2026-08-10—
2026-08-09−0.47
2026-08-08—
2026-08-07—
2026-08-06−1.58
2026-08-05—
2026-08-04—
2026-08-03+0.23
Bin counts as a table
From °FTo °FDays
−25.00−22.500
−22.50−20.000
−20.00−17.500
−17.50−15.000
−15.00−12.502
−12.50−10.0013
−10.00−7.5039
−7.50−5.00100
−5.00−2.50213
−2.50+0.00248
+0.00+2.50143
+2.50+5.0054
+5.00+7.5017
+7.50+10.0011
+10.00+12.500
+12.50+15.000
+15.00+17.503
+17.50+20.002
+20.00+22.501
+22.50+25.001

Month by month

00Z bilinear instantaneous temperature, newest first.

MonthnMAE °FBias °F
2026-10622.33-1.59
2026-09882.50-1.16
2026-08663.11-2.09
2026-07512.86-1.97
2026-06593.49-2.34
2026-05832.96-2.21
2026-04963.36-0.49
2026-031204.15-1.87
2026-021124.35-2.64
2026-011103.30-1.91

Availability

The scored period behind each model at this station, on a shared scale.

ModelScored periodDaysCoverage
GraphCast (GFS init)2026-01-04 → 2026-10-25203
GraphCast (GFS init)2026-01-04 → 2026-10-25203
GraphCast (GFS init)2026-01-04 → 2026-10-27236
GraphCast (GFS init)2026-01-04 → 2026-10-27236

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, instantaneous temperature). Negative means GraphCast (GFS init) has the lower MAE. Two verdicts are given because they answer different questions: Holm corrects for the whole family of comparisons made in one displayed table and is the only one the leaderboards mark with ▼ or ▲; uncorrected is the single 95 % interval on its own, which over hundreds of thousands of published pairs calls about one in twenty apart by chance. Prefer Holm.

Other modelCommon daysMAE difference °FpDistinguishable (Holm)Distinguishable (uncorrected)
ECMWF AIFS Single51−0.06[−0.32, 0.23]0.701nono
Aurora (GFS init)52−0.43[−0.72, −0.17]0.002noyes
Aurora (IFS init)48+0.15[−0.23, 0.54]0.426nono
FourCastNet v2 (GFS init)52−0.35[−0.74, 0.00]0.054nono
FourCastNet v2 (IFS init)50−0.38[−0.96, 0.15]0.192nono
NCEP GFS51−0.53[−0.86, −0.22]0.004noyes
GraphCast (IFS init)49−0.04[−0.35, 0.27]0.813nono
ECMWF IFS HRES51−0.00[−0.36, 0.36]0.953nono
Pangu-Weather (GFS init)52+0.05[−0.27, 0.30]0.675nono
Pangu-Weather (IFS init)48+0.14[−0.12, 0.41]0.244nono
Persistence (baseline)49−2.99[−4.57, −1.54]0.002noyes

Cite this page

The address is stable; the numbers behind it are not. Always cite with an access date and the data-through date.

Short

CastCheck, KBOS graphcast_gfs lead 3, methodology v0.3.1, accessed 2026-10-28, https://castcheck.zifanzhang.com/station/KBOS/model/graphcast_gfs/lead/3/

Long

CastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KBOS (Boston Logan), model graphcast_gfs, lead day 3. Methodology version 0.3.1, schema version 0.3, data through 2026-10-28. Accessed 2026-10-28. https://castcheck.zifanzhang.com/station/KBOS/model/graphcast_gfs/lead/3/ doi:10.5281/zenodo.22212363

Accessed

2026-10-28 (data through 2026-10-28; page built )