Kalshi Backtest: "Reading the Thermometer"

Can we predict CLI settlement within ±2°F by watching METAR readings during trading windows? Data: Sep 1, 2025 – Feb 18, 2026 (171 days, 7 stations).

Overall Results

69.1%
Lows within ±2°F (827/1197)
92.9%
Highs within ±2°F (1112/1197)
81.0%
Combined (1939/2394)
±1°F: 51.8% / 84.8%
Lows / Highs within ±1°F
±2°F: 69.1% / 92.9%
Lows / Highs within ±2°F
±3°F: 79.4% / 95.3%
Lows / Highs within ±3°F

Per-Station Breakdown

Station Lows ±1°F Lows ±2°F Lows ±3°F Lows Avg Diff Highs ±1°F Highs ±2°F Highs ±3°F Highs Avg Diff
KMDW
Chicago Midway
54% (92/171) 73% (124/171) 80% (136/171) 2.5°F 81% (138/171) 87% (148/171) 93% (159/171) 1.4°F
KNYC
NYC Central Park
60% (103/171) 73% (124/171) 82% (140/171) 2.6°F 80% (136/171) 87% (149/171) 90% (154/171) 1.3°F
KMIA
Miami
61% (104/171) 82% (141/171) 89% (153/171) 1.8°F 88% (150/171) 99% (169/171) 100% (171/171) 0.8°F
KLAX
Los Angeles
69% (118/171) 84% (144/171) 94% (160/171) 1.3°F 87% (149/171) 95% (163/171) 99% (169/171) 0.8°F
KAUS
Austin
30% (51/171) 51% (88/171) 67% (115/171) 3.6°F 89% (152/171) 97% (166/171) 98% (167/171) 1.0°F
KDEN
Denver
31% (53/171) 45% (77/171) 63% (107/171) 4.0°F 86% (147/171) 95% (162/171) 96% (165/171) 1.0°F
KPHL
Philadelphia
58% (99/171) 75% (129/171) 81% (139/171) 2.4°F 84% (143/171) 91% (155/171) 91% (156/171) 1.0°F

Worst Misses (METAR furthest from CLI)

LOWS - Top 10 Worst

DateStationCLI LowBest METARDiff
2025-12-20KDEN26°F51.0°F25.0°F
2025-12-14KAUS34°F56.0°F22.0°F
2025-12-28KMDW22°F43.0°F21.0°F
2026-01-14KMDW19°F40.0°F21.0°F
2025-11-10KNYC35°F55.0°F20.0°F
2026-01-15KNYC24°F44.0°F20.0°F
2026-02-07KNYC6°F26.0°F20.0°F
2025-10-04KDEN43°F63.0°F20.0°F
2025-11-11KDEN38°F57.0°F19.0°F
2025-12-18KMDW18°F36.0°F18.0°F

HIGHS - Top 10 Worst

DateStationCLI HighBest METARDiff
2026-01-14KMDW42°F23.0°F19.0°F
2025-12-14KAUS65°F46.0°F19.0°F
2026-02-07KPHL31°F15.0°F16.0°F
2025-12-13KMDW27°F12.0°F15.0°F
2026-02-07KNYC27°F12.0°F15.0°F
2026-01-09KMDW60°F47.0°F13.0°F
2026-01-19KMDW19°F7.0°F12.0°F
2025-12-17KLAX74°F63.0°F11.0°F
2026-01-24KAUS45°F34.0°F11.0°F
2026-01-23KMDW8°F-2.0°F10.0°F

Verdict

STRATEGY VALIDATED. During trading windows, METAR readings land within ±2°F of CLI settlement 81.0% of the time across all stations. The “reading the thermometer” approach works.