Highest temperature in NYC on July 9?

Platform comparison

Market context

The underlying event is a forecast for extreme heat at LaGuardia Airport on 9 July 2026, where the crowd-implied probability of a specific temperature range sits at 0% despite a current heatwave. Recent days have seen temperatures soar to 102°F in the city, with LaGuardia hitting 94°F at midnight, breaking previous records and establishing a dangerous heat index[1][3]. This intense, humid conditions with little overnight cooling suggest that the 0% probability may be a mispricing, as historical data indicates daytime highs in July typically reach 29°C (86°F), but recent anomalies have pushed peaks significantly higher[2][6].

Traders should monitor the continuation of this heatwave and any official weather service updates regarding the 104°F–106°F range, which some analysts fear could repeat this summer[7]. The primary catalyst is the persistence of strong sunshine and high UV levels, which are driving the current dangerously high heat index values across the Northeast[1]. While prediction markets like Robinhood and Lines.com show thin volume on related temperature contracts, the divergence between the 0% crowd probability and the analyst consensus on a potential record repeat highlights a significant opportunity for cross-platform odds comparison[4][5]. The settlement window ending in 2026 allows ample time for these weather patterns to evolve, making the current pricing vulnerable to correction.

Sources: 1 · 2 · 3 · 4 · 5

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

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 Best Prediction Markets UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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