Highest temperature in NYC on July 10?

Platform comparison

Market context

The market tracks the peak Fahrenheit reading at LaGuardia Airport on 10 July 2026, a date that falls immediately after an unprecedented East Coast heatwave. Just seven days prior, LaGuardia shattered its all-time record by hitting 104°F on 3 July, breaking a 60-year benchmark by three degrees [2]. This recent extremity means the 0% crowd-implied probability for any specific high range likely reflects a binary settlement logic rather than a belief that temperatures will be cool; the heat is already baked into the local atmospheric baseline.

Historical data shows LaGuardia’s July peaks rarely exceed 100°F, with the 101°F mark on 3 July 2026 standing as the new ceiling for the month [2][3]. Programmatic traders should model this market by fetching the Wunderground daily history endpoint for KLGA, filtering for the maximum value between 00:00 and 23:59 UTC, and mapping it against the resolution ranges. The key dependency is the official Wunderground record, which historically aligns with the National Weather Service timeseries but may lag by minutes during extreme volatility [2][10].

Traders must monitor the persistence of the current heat dome, which has already driven midnight temperatures to 94°F, a record itself [4][5]. While AccuWeather forecasts daily highs for mid-July 2026 between 73°F and 91°F, the immediate post-heatwave reality suggests a higher floor than the long-term average [1]. The catalyst is simply the absence of a cooling front; if the 3 July record persists as the seasonal maximum, the settlement will likely cluster near the upper bound of the 100–104°F range, making the 0% probability on lower ranges a rational reflection of the recent 104°F spike [2].

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 Kalshi Fees. 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 Kalshi Fees 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.