Illinois Weather Prediction Markets & Temperature Odds
Illinois weather prediction markets price what Chicago's thermometers and rain gauges will read, not what a forecast says. Each contract names its own airport station, Midway or O'Hare, and pays on that reading alone.
Chicago
90 open contracts · 3 observation daysCity board →- ≤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°—
Top Illinois Weather Markets
Chicago carries the Illinois weather board, and it asks three kinds of question. Two are daily: how high the temperature climbs and how low it falls. Each is written as a ladder of two-degree bands with an open band at each end, so the row covers every possible reading and exactly one band pays. Kalshi and Polymarket both list the daily high and low, and their ladders do not line up: on October 16, 2026, Kalshi's rows for the next day held six bands each and Polymarket's held eleven. The third question is monthly. Kalshi's rainfall contracts ask whether a month's total precipitation passes a whole-inch mark. The Chicago weather board carries every row, the station behind it and the settlement clock.
What Moves Illinois Weather Markets
Before the observation day, forecasts do the moving. The National Weather Service office for Chicago, based in Romeoville, issues the forecasts and the daily climate reports the contracts lean on, and each new forecast can push weight along a row toward warmer or cooler bands. Once the day is under way, measurements take over: a high that has already been reached cannot be undone, so the bands below it lose their value as the afternoon goes on. A rainfall contract moves the same way across a month, since each wet day adds to a total that never falls.
The station matters as much as the weather. The National Weather Service's afternoon climate reports for October 16, 2026 put the day's high at 58°F at Midway and 57°F at O'Hare, a single degree that can decide which band pays.
Why Illinois Weather Prediction Markets
A forecast gives one number. A ladder prices every band at once, and each price reads as the chance the market assigns that band, so a row shows the whole spread of expectations rather than one best guess, and it can disagree with the forecast. Settlement keeps the arithmetic clean: each contract names one station and one report, and the reading lands in a band or it does not. Kalshi's daily contracts read Midway through The Weather Company while Polymarket's read O'Hare from NOAA's hourly observations, so the same afternoon can settle two venues' rows on two different numbers. Every figure on the board is one venue's own price, never an average of the two.
Questions readers ask
How do weather prediction markets work in Illinois?
An exchange lists one contract per band of a reading, such as a Chicago daily high of 55°F to 56°F, and the band that holds the official reading pays in full while every other band pays nothing. Kalshi and Polymarket both list Chicago's daily high and low this way.
Which Illinois cities have weather prediction markets?
Chicago is the one Illinois city on the weather board, with daily high and low temperature ladders and monthly rainfall contracts. Another Illinois city would join once an exchange lists contracts for it, which is the exchange's decision.
How do Illinois weather markets settle?
On a named station's reading, never a forecast. Kalshi's daily high and low settle on the National Weather Service climate report for Chicago-Midway, CLIMDW, as The Weather Company reports it; Polymarket's settle on NOAA's hourly readings at O'Hare; Kalshi's monthly rainfall settles on the O'Hare climate report, CLIORD.
Where can I trade Illinois weather markets?
Kalshi and Polymarket both quoted Chicago temperature ladders on October 16, 2026, and the board's monthly rainfall contracts were Kalshi's. The board names the venue on each row, and no cell on this site links out to it.
Are weather prediction markets legal in Illinois?
The Illinois Predictions legal status page lists what the Illinois Gaming Board has said about prediction-market exchanges, each item with its date, and this page draws no legal conclusion of its own.