Settlement stations / KMDW

US · America/Chicago

Kalshi Chicago temperature: settles on KMDW

KMDW is Midway International, Chicago. Kalshi 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

Kalshi uses KMDW (Midway International). Polymarket settles the same city on KORD (O'Hare 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
KalshiNWS Climatological Report (CLI), relayed by The Weather Company
Source code CLIMDW. The daily climatological report is compiled from the full one-minute record, so it can print a high that the hourly reports never showed.		Fahrenheit2°Fhigh · low
KXHIGHCHI, KXLOWTCHI

Reporting and delay

Regular reports:53:53 past each hour, UTC — 1 regular report per hour.
Median delay3.5 minFrom the observation time in the report to the public NOAA feed. 26 reports, measured 2026-09-16.
90th percentile3.6 minOne report in ten is at least this late. Worth knowing before you trust a quiet hour.
Coordinates41.784, -87.755Local civil time: America/Chicago

Questions

Which weather station settles Chicago temperature contracts?

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

What is the resolution source for Kalshi Chicago temperature?

Kalshi names NWS Climatological Report (CLI), relayed by The Weather Company. Contracts settle in Fahrenheit on 2-degree buckets. The daily climatological report is compiled from the full one-minute record, so it can print a high that the hourly reports never showed.

When does KMDW report?

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

How long does a KMDW observation take to become public?

Measured over 26 hours on 2026-09-16, the median delay from the observation time in the report to its arrival on the public NOAA feed was 3.5 min, with a 90th percentile of 3.6 min across 26 reports. This moves with upstream conditions and is not a service level.

One email when plans open. No newsletter, and you can reply to unsubscribe.
WeatherTick tracks 67 settlement stations and publishes each day's running high and low already converted into the unit and bucket the contract settles in. Open the terminal for Chicago, 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.