Highest temperature in Chicago on July 15?

Platform comparison

Market context

Chicago’s highest temperature on 15 July 2026 at O’Hare International Airport is the real-world event determining this Polymarket contract, yet the market currently prices the YES outcome at 0%, reflecting near-total certainty that the temperature will not fall into the unspecified winning range implied by that side. Instead, the frontrunner is 94–95°F at 47%, with 96–97°F holding 35%, suggesting traders expect a hot but not extreme midsummer day [1].

Historically, Chicago July highs often cluster in the 90s, with the deadly 1995 heat wave producing sustained temperatures above 100°F and prompting emergency safety measures, including cooling centres and warnings against overexertion [2]. The current probability distribution aligns more closely with typical July patterns than with that outlier event, framing the 0% YES price as a rational bet against an unusually cool or moderate outcome rather than a denial of heat itself.

Traders should monitor the National Weather Service’s seven-day forecast for the Chicago metro area and any emerging heat advisories from the Illinois Emergency Management Agency, as these announcements directly influence temperature expectations. Wunderground’s daily history page for KORD will be the official resolution source, so real-time updates from that station on 15 July will settle the market, with USDC payouts executed on Polygon via conditional tokens once the data is confirmed [1].

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.