BELLWETHER SKYGOD Aug 19 2:50pm · NWS accuracy

How consistently NWS predicts each city's daily high, vs the settled actual. MAE = avg miss (°F), exact = landed in the settling integer, within 1°F = off by ≤1. Sorted most-consistent first. Caveat: still thin (forecasts only logged from Jun 27) - low n means luck, not skill. Becomes meaningful around 10-15 settled days per city; this page updates itself as data lands.
cities
20
1040 forecast/actual pairs
overall MAE
1.46 °F
avg miss, all cities
exact bucket
22%
landed the settling integer
within 1°F
60%
off by a degree or less
#CitynMAE °Fbiasexactwithin 1°F
1 Phoenix 52 1.00 -0.2 37% 79%
2 Miami 52 1.02 -0.4 29% 77%
3 Chicago 52 1.10 -0.7 29% 73%
4 Dallas 52 1.13 -0.1 29% 75%
5 Philadelphia 52 1.14 -0.2 38% 67%
6 Denver 52 1.23 -0.1 25% 69%
7 Austin 52 1.29 -1.0 17% 62%
8 Houston 52 1.38 +0.7 19% 60%
9 Atlanta 52 1.38 -0.4 21% 62%
10 Las Vegas 52 1.38 +0.5 31% 69%
11 Minneapolis 52 1.42 -0.0 25% 65%
12 San Antonio 52 1.42 +0.0 15% 60%
13 New Orleans 52 1.44 +0.4 19% 60%
14 Washington DC 52 1.54 -0.4 12% 58%
15 Oklahoma City 52 1.60 -0.1 17% 46%
16 Boston 52 1.73 -0.7 23% 54%
17 Los Angeles 52 1.79 +0.5 19% 52%
18 NYC 52 1.90 +0.9 13% 38%
19 Seattle 52 2.02 +0.5 17% 44%
20 San Francisco 52 2.31 +0.9 10% 40%
Green MAE ≤1°F · amber ≤2°F · red >2°F. bias + = NWS runs hot, − = runs cold.
Feeds the per-city confidence weight for Chalk: stake more where NWS is reliable, less where it isn't.