Highest temperature in Chicago on July 27?

Platform comparison

Market context

Chicago's peak temperature on 27 July 2026 will be measured at O'Hare International Airport and resolved against historical weather data from Wunderground. The market currently shows 0% implied probability across all temperature ranges, reflecting either a technical issue with the market's initialisation or genuine uncertainty about which bracket will ultimately contain the day's high. Traders settling positions via USDC on Polygon will need to wait until the National Weather Service publishes the official daily maximum for that date before conditional tokens resolve.

July temperatures at O'Hare typically range between 75°F and 85°F, though the airport has recorded highs exceeding 90°F during heat waves. The station's historical record for July sits at 97°F, set in 1988. Recent summers have shown increasing frequency of days above 85°F, with 2023 and 2024 both producing multiple heat events. The current 0% reading suggests the market may lack sufficient liquidity or participants to establish meaningful price discovery across the available temperature brackets.

Weather forecasting accuracy for a specific date fourteen months ahead remains limited, though seasonal patterns and climate data can inform positioning. Traders should monitor the National Weather Service's extended outlook as July 2026 approaches, particularly any signals of anomalous heat patterns or atmospheric conditions that might shift probabilities. The settlement mechanism depends entirely on Wunderground's historical records for KORD station, making data availability the critical dependency for final resolution.

Methodology

We track Highest temperature in Chicago on July 27? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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 PolyGram 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.