PolyWeatherLab
What Polymarket priced, what the weather models said, and what actually happened.

Istanbul highs

The market this page measures: highest temperature in Istanbul on 28 September 2026 on Polymarket
Whatever the market priced for 2026-09-28, what every weather model forecasts for the same day, and what actually happened, all in °C. The gap column is how far a model sits from the market: above the market it ran warm, below it ran cool. Resolves on station istanbul-airport.
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models say
19.3 °C
avg of 9 models
market's pick
19.0 °C
56.50% on this strike
gap
+0.17 °C
spread 1.4 °C
actual
not resolved yet

Market odds for 2026-09-28

What Polymarket is paying for each temperature. Each price is the market's probability that the day lands in that strike, so they add up to about 100%. Latest reading 2026-09-28 09:21 UTC, shown in °C.
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temperature °Codds
15.0 °C0.05%
16.0 °C0.05%
17.0 °C0.05%
18.0 °C0.05%
19.0 °C56.50%
20.0 °C42.50%
21.0 °C1.50%
22.0 °C0.20%
23.0 °C0.05%

Every forecast for 2026-09-28

Each model's newest reading for this day, in °C, taken 2026-09-28 06:40 to 08:00 UTC. Gap is the difference from the market, in degrees: a model above the market ran warm, one below ran cool.
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modelforecast °Cgap vs market °C
THE MARKET19.5––
ukmo seamless18.7-0.8
ncep gfs global18.8-0.7
jma gsm18.9-0.6
cma grapes global19.0-0.5
meteofrance arpege world19.0-0.5
ecmwf ifs02519.2-0.3
best match20.1+0.6
dwd icon eu20.1+0.6
dwd icon global20.1+0.6

How the forecasts moved

Every reading we hold for 2026-09-28, newest column first, in °C. The bracket under each time says how long before the day that reading was taken (or after, once the day has started), so the table reads right to left as the day approached. A model still moving in the last day is a model that has not settled, and that is the one to distrust. Older readings are kept but not shown.
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model09-28 08:00 (11h after)09-28 07:30 (11h after)09-28 06:40 (10h after)09-28 06:30 (10h after)09-28 06:07 (9h after)09-28 06:00 (9h after)
THE MARKET––––19.519.5
best match––20.1–20.120.1
cma grapes global––19.019.019.9–
dwd icon eu––20.1–20.120.1
dwd icon global––20.1–20.1–
ecmwf ifs02519.2–19.4–19.4–
jma gsm––18.9–18.9–
meteofrance arpege world––19.0–19.0–
ncep gfs global––18.8–18.8–
ukmo seamless–18.719.3–19.3–