Highest temperature in Chicago on July 15?

Platform comparison

Market context

On 15 July 2026, the highest temperature recorded at Chicago O’Hare International Airport will determine the outcome of a weather prediction market. In this market, a YES share pays out if the temperature falls within a specific range you select, while a NO share pays out if it falls outside that range. The settlement window closes at 12:00 UTC on that day, with Wunderground serving as the official resolution source for the peak Fahrenheit reading at station KORD.

Historical July highs in Chicago often cluster between 90°F and 98°F, with the 1995 heat wave producing extreme readings that still inform current risk assessments. The crowd currently assigns a 0% probability to the lowest range options, reflecting confidence that temperatures will exceed 90°F. Market frontrunners suggest 94–95°F at 45% and 96–97°F at 41%, indicating traders expect a hot but not record-breaking day [1].

Traders should monitor daily weather forecasts from the National Weather Service and local Chicago outlets for evolving heat advisories, as sudden shifts in cloud cover or wind patterns can alter peak temperatures. Recent reports highlight that scorching temperatures in the Chicago area are rivaling the deadly 1995 heat wave, underscoring the volatility of midsummer heat events [2]. No official announcements are expected before settlement, but real-time updates from Wunderground and regional meteorological services will be critical for validating the final outcome.

Sources: 1 · 2

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Market 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.