Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

CastCheck methodology v0.2 · data through 2026-08-30

All stations (mean of daily station errors) · ECMWF IFS HRES · lead day 2

ALL · ifs_hres · lead 2

Target day = initialization date + 2 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, ifs-gpid161, starting 2026-08-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 2 carry a QC flag on the observation.

JSON for this page CSV of the daily errors Cite this page

Every number for this combination

All four windows × both initializations × both interpolations × both variables. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval. MAE debiased and skill, debiased remove the constant offset of the window first, so a station that the model always reads a degree too warm is not scored as if it had no skill — compare the two skill columns to see how much of the error is a fixed offset. n QC next to n counts days whose observation carries a QC flag.

VariableInitMethod Windown MAE °F MAE debiased Bias °F RMSE °F ±1 °F±2 °F±3 °F Skill Skill, debiased Period
tmax00Zbilinear30d23 2 QC3.43 [3.26, 3.57]0.42-2.65 [-2.94, -2.38]4.10 [3.98, 4.23]16% [12%, 21%]29%46%-0.09+0.592026-08-03 → 2026-08-30
tmax00Zbilinear90d23 2 QC3.43 [3.25, 3.58]0.42-2.65 [-3.00, -2.38]4.10 [3.97, 4.25]16% [12%, 23%]29%46%-0.09+0.592026-08-03 → 2026-08-30
tmax00Zbilinear365d23 2 QC3.43 [3.25, 3.57]0.42-2.65 [-3.00, -2.35]4.10 [3.97, 4.25]16% [12%, 23%]29%46%-0.09+0.592026-08-03 → 2026-08-30
tmax00Zbilinearall23 2 QC3.43 [3.24, 3.59]0.42-2.65 [-3.01, -2.37]4.10 [3.96, 4.27]16% [12%, 22%]29%46%-0.09+0.592026-08-03 → 2026-08-30
tmax00Znearest30d23 2 QC3.63 [3.52, 3.74]0.47-2.62 [-2.97, -2.29]4.38 [4.20, 4.56]13% [11%, 17%]29%45%-0.15+0.552026-08-03 → 2026-08-30
tmax00Znearest90d23 2 QC3.63 [3.51, 3.76]0.47-2.62 [-3.02, -2.28]4.38 [4.18, 4.58]13% [10%, 18%]29%45%-0.15+0.552026-08-03 → 2026-08-30
tmax00Znearest365d23 2 QC3.63 [3.50, 3.77]0.47-2.62 [-3.04, -2.25]4.38 [4.17, 4.59]13% [10%, 17%]29%45%-0.15+0.552026-08-03 → 2026-08-30
tmax00Znearestall23 2 QC3.63 [3.50, 3.75]0.47-2.62 [-3.02, -2.27]4.38 [4.16, 4.58]13% [11%, 17%]29%45%-0.15+0.552026-08-03 → 2026-08-30
tmax12Zbilinear30d22 2 QC3.65 [3.45, 3.84]0.62-3.05 [-3.41, -2.68]4.38 [4.15, 4.60]12% [10%, 17%]28%46%-0.15+0.402026-08-03 → 2026-08-30
tmax12Zbilinear90d22 2 QC3.65 [3.44, 3.88]0.62-3.05 [-3.51, -2.61]4.38 [4.15, 4.66]12% [10%, 19%]28%46%-0.15+0.402026-08-03 → 2026-08-30
tmax12Zbilinear365d22 2 QC3.65 [3.44, 3.87]0.62-3.05 [-3.51, -2.62]4.38 [4.14, 4.64]12% [10%, 18%]28%46%-0.15+0.402026-08-03 → 2026-08-30
tmax12Zbilinearall22 2 QC3.65 [3.44, 3.86]0.62-3.05 [-3.51, -2.59]4.38 [4.12, 4.64]12% [10%, 18%]28%46%-0.15+0.402026-08-03 → 2026-08-30
tmax12Znearest30d22 2 QC3.80 [3.56, 4.06]0.68-3.01 [-3.43, -2.56]4.63 [4.30, 4.95]13% [10%, 18%]28%43%-0.20+0.342026-08-03 → 2026-08-30
tmax12Znearest90d22 2 QC3.80 [3.54, 4.10]0.68-3.01 [-3.55, -2.48]4.63 [4.28, 4.97]13% [10%, 19%]28%43%-0.20+0.342026-08-03 → 2026-08-30
tmax12Znearest365d22 2 QC3.80 [3.54, 4.11]0.68-3.01 [-3.55, -2.49]4.63 [4.27, 4.98]13% [10%, 19%]28%43%-0.20+0.342026-08-03 → 2026-08-30
tmax12Znearestall22 2 QC3.80 [3.54, 4.09]0.68-3.01 [-3.55, -2.43]4.63 [4.25, 4.97]13% [10%, 19%]28%43%-0.20+0.342026-08-03 → 2026-08-30
tmin00Zbilinear30d23 2 QC2.53 [2.37, 2.73]0.64+1.32 [1.05, 1.60]3.30 [3.06, 3.54]27% [20%, 31%]49%68%+0.12+0.232026-08-03 → 2026-08-30
tmin00Zbilinear90d23 2 QC2.53 [2.38, 2.78]0.64+1.32 [1.02, 1.65]3.30 [3.05, 3.61]27% [16%, 31%]49%68%+0.12+0.232026-08-03 → 2026-08-30
tmin00Zbilinear365d23 2 QC2.53 [2.35, 2.79]0.64+1.32 [1.02, 1.69]3.30 [3.02, 3.61]27% [16%, 32%]49%68%+0.12+0.232026-08-03 → 2026-08-30
tmin00Zbilinearall23 2 QC2.53 [2.37, 2.86]0.64+1.32 [1.01, 1.70]3.30 [3.04, 3.68]27% [16%, 32%]49%68%+0.12+0.232026-08-03 → 2026-08-30
tmin00Znearest30d23 2 QC2.69 [2.48, 2.91]0.64+1.42 [1.18, 1.68]3.53 [3.24, 3.83]27% [22%, 31%]48%64%+0.06+0.242026-08-03 → 2026-08-30
tmin00Znearest90d23 2 QC2.69 [2.50, 2.97]0.64+1.42 [1.15, 1.72]3.53 [3.24, 3.91]27% [20%, 31%]48%64%+0.06+0.242026-08-03 → 2026-08-30
tmin00Znearest365d23 2 QC2.69 [2.46, 2.97]0.64+1.42 [1.13, 1.78]3.53 [3.20, 3.92]27% [20%, 31%]48%64%+0.06+0.242026-08-03 → 2026-08-30
tmin00Znearestall23 2 QC2.69 [2.47, 3.02]0.64+1.42 [1.12, 1.76]3.53 [3.21, 3.99]27% [20%, 31%]48%64%+0.06+0.242026-08-03 → 2026-08-30
tmin12Zbilinear30d22 2 QC2.38 [2.24, 2.60]0.57+1.14 [0.82, 1.53]3.08 [2.86, 3.40]29% [24%, 34%]52%69%+0.18+0.352026-08-03 → 2026-08-30
tmin12Zbilinear90d22 2 QC2.38 [2.24, 2.71]0.57+1.14 [0.77, 1.65]3.08 [2.87, 3.50]29% [22%, 34%]52%69%+0.18+0.352026-08-03 → 2026-08-30
tmin12Zbilinear365d22 2 QC2.38 [2.23, 2.67]0.57+1.14 [0.73, 1.70]3.08 [2.85, 3.50]29% [22%, 35%]52%69%+0.18+0.352026-08-03 → 2026-08-30
tmin12Zbilinearall22 2 QC2.38 [2.22, 2.74]0.57+1.14 [0.73, 1.64]3.08 [2.86, 3.54]29% [22%, 35%]52%69%+0.18+0.352026-08-03 → 2026-08-30
tmin12Znearest30d22 2 QC2.52 [2.35, 2.78]0.58+1.23 [0.91, 1.63]3.32 [3.04, 3.68]28% [25%, 31%]51%68%+0.12+0.332026-08-03 → 2026-08-30
tmin12Znearest90d22 2 QC2.52 [2.37, 2.89]0.58+1.23 [0.85, 1.76]3.32 [3.04, 3.79]28% [23%, 31%]51%68%+0.12+0.332026-08-03 → 2026-08-30
tmin12Znearest365d22 2 QC2.52 [2.34, 2.86]0.58+1.23 [0.80, 1.81]3.32 [3.01, 3.78]28% [23%, 32%]51%68%+0.12+0.332026-08-03 → 2026-08-30
tmin12Znearestall22 2 QC2.52 [2.35, 2.93]0.58+1.23 [0.81, 1.74]3.32 [3.03, 3.88]28% [23%, 31%]51%68%+0.12+0.332026-08-03 → 2026-08-30

+ model too warm · − model too cold · bias interval includes zero · ★ lowest MAE · = not distinguishable from the leader · ▼ significantly worse · n < 30 greyed and unranked · CI is a 95 % moving-block bootstrap interval.

Daily error, last 90 days

Daily forecast minus observed error in °F for ECMWF IFS HRES at ALL, lead day 2, 00Z bilinear tmax+5+2.50-2.5-52026-08-03: -3.21 °F2026-08-08: -2.65 °F2026-08-09: -2.17 °F2026-08-10: -2.64 °F2026-08-11: -1.91 °F2026-08-13: -2.64 °F2026-08-14: -2.76 °F2026-08-15: -1.94 °F2026-08-16: -1.51 °F2026-08-17: -2.58 °F2026-08-18: -2.66 °F2026-08-19: -2.76 °F2026-08-20: -3.11 °F2026-08-21: -1.73 °F2026-08-22: -2.85 °F2026-08-23: -2.86 °F2026-08-24: -3.67 °F2026-08-25: -2.29 °F2026-08-26: -2.91 °F2026-08-27: -3.29 °F2026-08-28: -3.91 °F2026-08-29: -2.62 °F2026-08-30: -2.33 °F2026-08-032026-08-30°F, forecast − observed
Forecast − observed, °F, 00Z bilinear daily maximum. 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. Hover a point for its date and value.
The same series as a table (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.33
2026-08-29-2.62
2026-08-28-3.91
2026-08-27-3.29
2026-08-26-2.91
2026-08-25-2.29
2026-08-24-3.67
2026-08-23-2.86
2026-08-22-2.85
2026-08-21-1.73
2026-08-20-3.11
2026-08-19-2.76
2026-08-18-2.66
2026-08-17-2.58
2026-08-16-1.51
2026-08-15-1.94
2026-08-14-2.76
2026-08-13-2.64
2026-08-12—
2026-08-11-1.91
2026-08-10-2.64
2026-08-09-2.17
2026-08-08-2.65
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03-3.21

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at ALL, lead day 2-5 to -4.5 °F: 0 days-4.5 to -4 °F: 0 days-4 to -3.5 °F: 2 days-3.5 to -3 °F: 3 days-3 to -2.5 °F: 11 days-2.5 to -2 °F: 3 days-2 to -1.5 °F: 4 days-1.5 to -1 °F: 0 days-1 to -0.5 °F: 0 days-0.5 to 0 °F: 0 days0 to 0.5 °F: 0 days0.5 to 1 °F: 0 days1 to 1.5 °F: 0 days1.5 to 2 °F: 0 days2 to 2.5 °F: 0 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 0 days4 to 4.5 °F: 0 days4.5 to 5 °F: 0 daysdashed: P50 |e| 2.65 · P90 |e| 3.28 °F-50+5 °Fn = 23 days
All scored days for 00Z bilinear daily maximum, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides. Hover a bar for its bin and count.
Bin counts as a table
From °FTo °FDays
-5.00-4.500
-4.50-4.000
-4.00-3.502
-3.50-3.003
-3.00-2.5011
-2.50-2.003
-2.00-1.504
-1.50-1.000
-1.00-0.500
-0.50+0.000
+0.00+0.500
+0.50+1.000
+1.00+1.500
+1.50+2.000
+2.00+2.500
+2.50+3.000
+3.00+3.500
+3.50+4.000
+4.00+4.500
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08232.65 -2.65

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-03 → 2026-08-30 23
ECMWF IFS HRES2026-08-03 → 2026-08-30 23
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 2026-08-30 22

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 23 -0.20 [-0.49, 0.09] no
Aurora (IFS init) 1 -1.75 [-1.75, -1.75] yes
FourCastNet v2 (IFS init) 1 -0.38 [-0.38, -0.38] yes
NCEP GFS 23 +0.27 [-0.17, 0.55] no
GraphCast (IFS init) 21 -1.68 [-1.99, -1.35] yes
Pangu-Weather (IFS init) 1 -0.76 [-0.76, -0.76] yes
Persistence (baseline) 23 +0.28 [-0.01, 0.65] no

Cite this page

ShortCastCheck, ALL ifs_hres lead 2, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/ALL/model/ifs_hres/lead/2/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: ALL (All stations (mean of daily station errors)), model ifs_hres, lead day 2. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/ALL/model/ifs_hres/lead/2/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

JSON CSV all scores methodology v0.2 licence