Both markets settle on Sea-Tac (KSEA), but they count the high differently.
Sea-Tac (KSEA)
The day's official high, 1 AM to 1 AM while clocks are on daylight time.
Seattle-Tacoma International Airport (KSEA)
The highest hourly reading on NOAA's page for the station, in whole degrees, on the local calendar day.
Highest hourly reading so far at Seattle-Tacoma International Airport (KSEA): 42°F at 12:53 AM. The line is each hourly report, the reports Polymarket's rules count; the stripes are its ranges.
Seattle so far today: the high is 42°F (12:53 AM), in the 45° or below bracket. The favorite is 54° to 55° at 50¢ (Polymarket, 30 minutes late), 12° above the high so far. The day ends at 12:00 AM PDT. 4 reports from KSEA from 12:00 AM to 4:17 AM PDT, between 40°F and 42°F; the latest 41°F at 3:53 AM.
| Bracket | Price | Note |
|---|---|---|
| 64° or above | <1¢ | |
| 62° to 63° | <1¢ | |
| 60° to 61° | <1¢ | |
| 58° to 59° | <1¢ | |
| 56° to 57° | 8¢ | |
| 54° to 55° | 50¢ | favorite |
| 52° to 53° | 41¢ | |
| 50° to 51° | 3¢ | |
| 48° to 49° | <1¢ | |
| 46° to 47° | <1¢ | |
| 45° or below | <1¢ | high so far |
| Time | Reading |
|---|---|
| 3:53 AM | 41°F |
| 2:53 AM | 40°F |
| 1:53 AM | 40°F |
| 12:53 AM | 42°F |
| Range | Price (30 min late) | Traded |
|---|---|---|
| 64° or above | <1¢ | 105 |
| 62°–63° | <1¢ | 394 |
| 60°–61° | <1¢ | 414 |
| 58°–59° | <1¢ | 771 |
| 56°–57° | 8¢ | 3,195 |
| 54°–55° | 50¢ | 3,797 |
| 52°–53° | 41¢ | 3,682 |
| 50°–51° | 3¢ | 2,745 |
| 48°–49° | <1¢ | 1,005 |
| 46°–47° | <1¢ | 514 |
| 45° or belowhigh so far | <1¢ | 319 |
Almanac's °F is each report's tenths of a degree Celsius, rounded. Polymarket settles on NOAA's page for the station, which lists the same reports. Today's market on Polymarket.
Which range will Seattle settle on today? For fun: no money, no orders, nothing sent to Polymarket. It counts on the weekly leaderboard: a right call scores 100 minus its price when you called it.
Create a free account to make your call.
Polymarket's winning range held the high Kalshi settled on for 23 of 30 days; it cooler on 7.
Source: Kalshi's settlements: Kalshi's public market data; Polymarket's results: each daily event
| Rule | Kalshi | Polymarket |
|---|---|---|
| What counts as the high | The day's official high for the station, as The Weather Company publishes it for Kalshi (weather.com/kalshi) for events from Aug 14, 2026. It has matched the NWS climate report's official high on 1,587 of 1,588 settled days, and that high counts a peak between hourly reports. | The highest reading in the "Temp" column of NOAA's time-series page for the station, using its hourly data, in whole degrees. A peak between two readings isn't in that column, so it can come out lower than the official high. |
| The day | Midnight to midnight local standard time, so 1 AM to 1 AM while clocks are on daylight time. | Every time listed on that day on NOAA's page, which shows the station's local clock time. |
| The ranges | Two-degree brackets, with an open bracket at each end. Where the brackets start moves from day to day (61°–62° one day, 62°–63° another). | Two-degree ranges that start on an even number (62°–63°), with an open range at each end. |
| When it settles | After the final report for the day is out, usually the next morning. | Once the first reading of the next day is on NOAA's page, or by 11:59 PM Eastern the next day. If NOAA has no data by then, the Weather Underground daily observations table is used. |
Source: Polymarket's market rules (read Thu, Oct 22); Kalshi contract terms; The Weather Company's Kalshi data
All 11 cities, Kalshi vs Polymarket
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