Chicago Weather Prediction Markets & Temperature Odds
Chicago's daily high and low temperature odds and its monthly rainfall contracts, band by band. Kalshi settles its daily rows at Midway and Polymarket at O'Hare, so read the station before the number.
The board
8 ladders · Today · Tomorrow · Tuesday, Oct 20 · This month · November 2026- ≤53°<1%+99900POLY
- 54–55°<1%+99900POLY
- 56–57°<1%+99900POLY
- 58–59°1%+19900POLY
- ≤60°2%+4900KAL
- 60–61°17%+488POLY
- 61–62°9%+1011KAL
- 62–63°52%-108POLY
- 63–64°73%-270KAL
- 64–65°30%+233POLY
- 65–66°16%+525KAL
- 66–67°1%+11011POLY
- 67–68°1%+9900KAL
- 68–69°<1%+33233POLY
- ≥69°1%+9900KAL
- 70–71°<1%+99900POLY
- ≥72°<1%+99900POLY
- ≤33°1%+9900POLY
- ≤34°1%+9900KAL
- 34–35°—POLY
- 35–36°2%+4900KAL
- 36–37°—POLY
- 37–38°1%+9900KAL
- 38–39°—POLY
- 39–40°1%+9900KAL
- 40–41°—POLY
- 41–42°100%—KAL
- 42–43°96%-2400POLY
- ≥43°1%+9900KAL
- 44–45°<1%+99900POLY
- 46–47°<1%+99900POLY
- 48–49°<1%+99900POLY
- 50–51°<1%+99900POLY
- ≥52°<1%+99900POLY
- ≤55°<1%+99900
- 56–57°<1%+99900
- 58–59°<1%+99900
- 60–61°<1%+49900
- 62–63°1%+11011
- 64–65°3%+3233
- 66–67°50%-100
- 68–69°42%+138
- 70–71°4%+2400
- 72–73°<1%+33233
- ≥74°<1%+99900
- ≤33°—
- 34–35°—
- 36–37°—
- 38–39°—
- 40–41°—
- 42–43°—
- 44–45°—
- 46–47°—
- 48–49°—
- 50–51°—
- ≥52°—
- ≤57°<1%+49900
- 58–59°<1%+49900
- 60–61°2%+4900
- 62–63°<1%+49900
- 64–65°7%+1329
- 66–67°23%+335
- 68–69°50%-100
- 70–71°18%+456
- 72–73°1%+9900
- 74–75°<1%+49900
- ≥76°1%+9900
- ≤37°—
- 38–39°—
- 40–41°—
- 42–43°—
- 44–45°—
- 46–47°—
- 48–49°—
- 50–51°—
- 52–53°—
- 54–55°—
- ≥56°—
- >3 in40%+150
- >4 in16%+525
- >5 in12%+733
- >6 in2%+4900
- >7 in7%+1329
- >1 in88%-733
- >2 in67%-203
- >3 in42%+138
- >4 in19%+426
- >5 in9%+1011
- >6 in4%+2400
- >7 in13%+669
Which Station Settles a Chicago Contract
Chicago has no single official thermometer for these markets; each venue names its own. Kalshi's daily high and low ladders, the KXHIGHCHI and KXLOWTCHI series, settle on the maximum or minimum temperature "recorded at Chicago (CLIMDW)" as The Weather Company reports it. CLIMDW is the National Weather Service's daily climate report for Chicago-Midway, issued by the Chicago office in Romeoville, and the station behind it is KMDW at Chicago Midway Airport.
Polymarket's daily high and low read a different airport. Its rules settle on the highest or lowest temperature recorded by NOAA at the Chicago O'Hare International Airport station, KORD, taken from the "Temp" column of the National Weather Service's hourly observations in whole degrees. Kalshi's monthly rainfall contracts also sit at O'Hare: they read the total precipitation in CLIORD, the O'Hare climate report.
The two airports do not always agree. The National Weather Service's afternoon reports for October 16, 2026 had the day's high at 58°F at Midway and 57°F at O'Hare, which is enough to put a Kalshi row and a Polymarket row for the same day in different bands.
How the Chicago Ladders Are Built
Each observation day carries a high row and a low row, priced as separate questions about the same day. Kalshi's rows are six bands: four two-degree bands with an open band at each end. For October 17, 2026 its high ladder ran from 52°F or below to 61°F or above, and a band such as 55° to 56° pays on a reading of 55 or 56, both ends included. Polymarket's rows for the same day ran eleven bands, from 47°F or below to 66°F or higher. Polymarket also lists further ahead: its October 17 events opened early on October 15, while Kalshi's opened at 9 a.m. Central on October 16.
The rainfall contracts are built differently. Each one asks whether the month's total at O'Hare is strictly greater than a whole number of inches, from 1 through 7 for October 2026, so a wet month can settle several thresholds Yes at once. Along a temperature row, by contrast, exactly one band pays, and the prices read as one spread of chances.
When a Chicago Contract Settles
Kalshi's temperature terms rank their sources, The Weather Company first and the National Weather Service second, and count only the first official report that is not marked preliminary, read at its full precision. Revisions after expiration are ignored, and settlement follows no later than the day after expiration. Kalshi's October 17, 2026 rows trade until 1 a.m. Central on October 18.
Polymarket's Chicago contracts resolve once NOAA publishes the first reading for the following day, or by 11:59 p.m. Eastern the day after the observation date, whichever comes first. If NOAA's data is missing by then, the rules turn to Weather Underground's daily observations, and with no data at all the market resolves to the lowest band.
A rainfall contract waits for the month to finish. Kalshi's terms use the first National Weather Service daily climate report that covers every day of the month, count a trace of rain as zero, and ignore later corrections. The October 2026 contracts stop trading at 10:59 p.m. Central on October 31.
What the Chicago Board Leaves Out
Only temperature and rainfall trade here; no snowfall contract was on the Chicago board on October 16, 2026, and a day or month that has been measured and closed leaves it. Each row names its venue, no cell on the page links out, and a Kalshi band is never averaged or paired with a Polymarket band, because the two read different stations. Other Illinois cities would join the Illinois weather hub once an exchange lists contracts for them, and the legal status page covers what the Illinois Gaming Board has said about the exchanges that quote these rows.
Questions readers ask
Which weather station settles a Chicago temperature market?
Kalshi's daily high and low settle at Chicago Midway Airport through the National Weather Service's CLIMDW report, as The Weather Company reports it, while Polymarket's daily high and low settle on NOAA's hourly readings at O'Hare, station KORD. The station is part of each venue's contract, not a property of the city.
Why can Midway and O'Hare show different Chicago temperatures?
They are separate stations at two airports, each with its own readings. The National Weather Service's afternoon reports for October 16, 2026 had the high at 58°F at Midway and 57°F at O'Hare, so a Kalshi row and a Polymarket row for the same day can settle on different figures.
When does a Chicago daily temperature contract settle?
Kalshi's terms use the first official non-preliminary report and settle no later than the day after expiration; its October 17, 2026 rows trade until 1 a.m. Central on October 18. Polymarket resolves once NOAA posts the next day's first reading, or by 11:59 p.m. Eastern the day after the observation date.
Is there a Chicago rain market?
Yes. Kalshi lists monthly Chicago precipitation contracts that ask whether the month's total at O'Hare, from the National Weather Service's CLIORD report, is greater than a whole number of inches; the October and November 2026 months were both open on October 16, 2026.
What happens if the Chicago reading is not published?
Kalshi's terms fall back from The Weather Company to the National Weather Service, and with no data by the expiration date every band settles at the last fair price the exchange determines. Polymarket turns to Weather Underground if NOAA's data is missing by 11:59 p.m. Eastern the next day, and resolves to the lowest band if there is none.