Paste a METAR and get the station's exact °F from its T-group, plus the 6-hour and 24-hour maximum and minimum groups. Free, in your browser.
KNYC (Central Park, New York City), 11:51 UTC on the 19th. Ends in “$”: the station's own check flags it for maintenance.
The body's 09/07 is whole degrees Celsius: 9°C could be any of 48°F, 49°F. Use the T-group instead.
What Polymarket would read
Kalshi settles on the day's official high from the climate report, not on any one report.
°F = °C × 9/5 + 32, rounded to the whole degree. The station stores whole °F and reports tenths of a degree Celsius, so the rounding gives the stored value back; a reading more than 0.1°F from a whole degree is marked.
Settlement stations keep whole degrees Fahrenheit and report them in degrees Celsius. The METAR's body ("09/07") rounds to whole °C, which can stand for two or three different °F. The T-group in the remarks gives tenths of a degree, and converting it back gives the stored whole °F exactly.
Hourly reports can miss the peak. The 6-hour maximum (on the reports near 00, 06, 12 and 18 UTC) and the 24-hour maximum (on the report nearest local standard midnight) catch what happened in between.
None of these is the official high. The market settles on the day's climate report, which can be higher than every report (a peak between them) or, now and then, lower (when the NWS discards a reading).
Source: NWS Chicago: weather observations FAQ; ASOS User's Guide; aviationweather.gov data API (live METARs)
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