Research & track record
Forecasts are scored against what the station actually recorded. Everything here is also on the API.
SIMULATEDResolved temperatures on this page are real — Open-Meteo analysis at the station coordinates, 5 stations, 90 days. The historical forecasts they are scored against are simulated: forecasts are archived from now on as they are issued, and this page switches to the real record as history accumulates. Full methodology →
90d MAE · daily high
1.15°
vs 1.57° best public model (ECMWF)
Days beating market
59%
our error < closing implied error
Simulated P&L, 90d
+$30K
per $10K bankroll · Kelly ¼
Brier score
0.120
vs market 0.143 — lower is better
Forecast error — daily high, 90d MAE
Sonde
1.15°
ECMWF
1.57°
GFS
1.78°
Open-Meteo
1.80°
ICON
2.14°
All 5 stations. Sonde beats the best public model by 0.42° — roughly one Kalshi bucket.
Cumulative strategy P&L — 90 days
$10K bankroll · Kelly ¼ · best bucket per marketCalibration — do our probabilities mean it?
WHEN WE SAY
IT HAPPENS
SAMPLES
10%
5.8%
1019
30%
33%
270
50%
48.5%
361
Brier 0.120 vs market 0.143. Well-calibrated probabilities are what make the EV column tradeable.
By station — 90d MAE, Sonde vs market-implied
STATION
SONDE
MARKET
ADVANTAGE
DAYS
Chicago KMDW
1.03°
1.64°
+0.61°
66
Miami KMIA
1.15°
1.56°
+0.41°
66
Phoenix KPHX
1.16°
1.42°
+0.26°
66
Los Angeles KLAX
1.18°
1.56°
+0.38°
66
Philadelphia KPHL
1.22°
1.89°
+0.67°
66
Recent resolutions
resolved value is real · forecasts are reconstructedDATE
MARKET
SONDE
MKT IMPLIED
RESOLVED
ERR·S
ERR·M
RESULT
07-29
Philadelphia · daily high
80.9°
82.0°
82°
1.2°
0.1°
LOSS −$105
07-29
Miami · daily high
94.0°
96.0°
93°
1.4°
3.4°
LOSS −$105
07-29
Chicago · daily high
80.5°
80.1°
79°
1.4°
1.0°
LOSS −$104
07-29
Phoenix · daily high
107.4°
108.1°
109°
1.5°
0.8°
LOSS −$105
07-29
Los Angeles · daily high
77.1°
79.4°
79°
1.4°
0.9°
LOSS −$106
07-28
Philadelphia · daily high
82.4°
84.4°
83°
0.4°
1.6°
WIN +$664
07-28
Miami · daily high
86.6°
90.2°
88°
1.1°
2.5°
NO TRADE
07-28
Chicago · daily high
74.1°
77.7°
77°
2.4°
1.2°
NO TRADE
07-28
Phoenix · daily high
104.4°
103.9°
105°
0.2°
0.7°
WIN +$328
07-28
Los Angeles · daily high
78.5°
78.3°
78°
0.7°
0.5°
NO TRADE
07-27
Philadelphia · daily high
84.0°
79.6°
85°
0.8°
5.2°
LOSS −$265
07-27
Miami · daily high
92.0°
92.7°
91°
0.9°
1.6°
NO TRADE
Bankroll $10K · quarter-Kelly · minimum 6¢ edge to take a position.