Highest temperature in NYC on July 12?

Platform comparison

Market context

An intense high-pressure system is dominating the Northeast on 12 July 2026, driving scorching temperatures and oppressive humidity across New York City and the wider East Coast. Forecasts indicate afternoon highs near 94°F in the city, with heat index values climbing to approximately 105°F due to humidity levels near 75%[2]. This active heatwave creates a stark divergence from the current crowd-implied probability of 0% for the “YES” outcome on the highest temperature contract, suggesting a significant mispricing between live weather conditions and market sentiment.

Historical data from LaGuardia Airport during recent July heatwaves shows the station frequently exceeding 90°F, with records reaching 102°F at midnight during the 2026 heat event[7]. Comparable cases, such as Newark hitting 103°F earlier in July 2026, demonstrate that temperatures in the region can surge well above the average July high of 84°F[3][6]. The 0% implied probability ignores these established patterns of extreme heat, where LaGuardia has previously recorded midnight temperatures exceeding 100°F, framing the current odds as unusually detached from climatic reality.

Traders should monitor real-time updates from Wunderground for the official LaGuardia reading, as the settlement relies exclusively on this source[2]. Key catalysts include the persistence of the high-pressure system and humidity levels, which are currently pushing heat indices to dangerous levels across the Mid-Atlantic[2]. Recent reports confirm heat alerts affecting much of the Northeast, with electricity demand rising as cooling systems run continuously[2]. The divergence between sportsbook lines, which may not yet reflect this specific weather event, and the prediction market’s flat odds presents a clear arbitrage opportunity for those tracking the live forecast.

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

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 PolyGram. 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.

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.