US · America/Los_Angeles
Kalshi, Polymarket and IBKR settle Seattle temperature on KSEA
KSEA is Seattle-Tacoma International, Seattle. Kalshi and Polymarket and IBKR ForecastEx settle 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.
How it settles
| Venue | Resolution source | Unit | Bucket | Contracts |
|---|---|---|---|---|
| Kalshi | NWS Climatological Report (CLI), relayed by The Weather Company Source code CLISEA. The daily climatological report is compiled from the full one-minute record, so it can print a high that the hourly reports never showed. Its day runs in local standard time all year. | Fahrenheit | 2°F Range contract | high · lowKXHIGHTSEA, KXLOWTSEA |
| Polymarket | Routine METAR reports published by aviationweather.gov Source code KSEA. 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. | Fahrenheit | 2°F Range contract | high · lowhighest-temperature-in-seattle, lowest-temperature-in-seattle |
| IBKR ForecastEx Also sold through Robinhood: same ticker, same settlement. | Weather Underground daily history table for this station Source code KSEA. That table carries hourly METARs and SPECIs only, over the local clock day, and prints whole degrees rounded. | Fahrenheit | 1°F ladder Exceeds X, one rung per degree | high · lowUHSEA, ULSEA |
Reporting and delay
Questions
Which weather station settles Seattle temperature contracts?
Kalshi, Polymarket and IBKR ForecastEx settle Seattle on KSEA, Seattle-Tacoma International.
What is the resolution source for Kalshi Seattle 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. Its day runs in local standard time all year.
What is the resolution source for Polymarket Seattle 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.
What is the resolution source for IBKR ForecastEx Seattle temperature?
IBKR ForecastEx names Weather Underground daily history table for this station. Contracts settle in Fahrenheit, as a ladder of contracts one degree apart that pay when the day's reading passes the strike. That table carries hourly METARs and SPECIs only, over the local clock day, and prints whole degrees rounded. Robinhood resells this same contract, at the same ticker and settlement.
When does KSEA report?
:53 past each hour, UTC — 1 regular report per hour.
How long does a KSEA 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 32 s, with a 90th percentile of 3 min 41 s across 27 reports. This moves with upstream conditions and is not a service level.
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