Settlement stations / KORD

US · America/Chicago

Polymarket settles Chicago temperature on KORD

KORD is O'Hare International, Chicago. Polymarket settles temperature contracts here. Below: the resolution source each venue names, when the station reports, and how long a reading takes to reach the public feed.

This city settles on two different stations

Polymarket uses KORD (O'Hare International). Kalshi and IBKR ForecastEx and Polymarket US settle the same city on KMDW (Midway International) instead. The two sites can report different temperatures at the same moment and land in different contract buckets on the same day, so a reading from one tells you nothing definitive about the other.

How it settles

VenueResolution sourceUnitBucketContracts
PolymarketRoutine METAR reports published by aviationweather.gov
Source code KORD. Every report not marked SPECI counts, off-hour ones included, read from the T group in tenths of a degree Celsius and rounded half up to a whole degree of the contract. It is the same report stream shown here, so the running high tracks it directly.		Fahrenheit2°F
Range contract		high · low
highest-temperature-in-chicago, lowest-temperature-in-chicago

Reporting and delay

Regular reports:51:51 past each hour, UTC — 1 regular report per hour.
Median delay3 min 11 sFrom the observation time in the report to the public NOAA feed. 39 reports, measured 2026-09-17.
90th percentile4 min 10 sOne report in ten is at least this late. Worth knowing before you trust a quiet hour.
Coordinates41.960, -87.932Local civil time: America/Chicago

Questions

Which weather station settles Chicago temperature contracts?

Polymarket settles Chicago on KORD, O'Hare International. Kalshi, IBKR ForecastEx and Polymarket US settle the same city on KMDW, Midway International, which is a different site.

What is the resolution source for Polymarket Chicago temperature?

Polymarket names Routine METAR reports published by aviationweather.gov. Contracts settle in Fahrenheit, on 2-degree buckets. Every report not marked SPECI counts, off-hour ones included, read from the T group in tenths of a degree Celsius and rounded half up to a whole degree of the contract. It is the same report stream shown here, so the running high tracks it directly.

When does KORD report?

:51 past each hour, UTC — 1 regular report per hour.

How long does a KORD observation take to become public?

Measured over 26 hours on 2026-09-17, the median delay from the observation time in the report to its arrival on the public NOAA feed was 3 min 11 s, with a 90th percentile of 4 min 10 s across 39 reports. This moves with upstream conditions and is not a service level.

KORD is live on the free plan: sign in with Google, GitHub or email, no card. Open it on the board.

WeatherTick tracks 76 settlement stations and publishes each day's running high and low already converted into the unit and bucket the contract settles in. Open Chicago on the board, or see every settlement station. Settlement always follows the resolution source named by the venue; the figures here are computed from the public feed and are not a settlement source.