Highest temperature in Chicago on July 15?

Platform comparison

Market context

Chicago’s highest temperature on 15 July 2026 at O’Hare International Airport will settle this Polymarket contract, with the crowd currently pricing a YES outcome at 0%. On Polygon, traders use USDC to buy conditional tokens representing temperature ranges, and the market resolves once Wunderground publishes the day’s peak Fahrenheit reading for KORD.

Historically, mid-July in Chicago often sees highs between 80°F and 95°F, with extreme heatwaves pushing past 100°F in years like 1995 and 2012. The 0% probability suggests the market expects the temperature to fall outside the specific range offered, likely because the range is set too low or too high relative to typical July peaks. Comparable cases show that when forecasts predict a heatwave, conditional token prices for higher ranges surge within days of the event.

Traders should monitor the National Weather Service’s 7-day forecast for Chicago, which typically updates daily and includes heat index projections. A recent alert from the NWS on 10 July 2026 noted rising humidity and potential for above-average temperatures through mid-month, though no extreme heat warning has been issued yet [1]. The key catalyst is the official high temperature recorded at KORD by 12:00 UTC on 15 July, as Wunderground’s data will determine the final resolution.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.