Highest temperature in NYC on July 15?

Platform comparison

Market context

New York City is currently riding a strong summer heatwave that peaks today and tomorrow, with forecasts pushing the highest temperature at LaGuardia Airport into the mid-to-upper 90s Fahrenheit. The crowd-implied probability of 0% for the YES outcome on this specific contract reflects a market consensus that the peak will not breach the highest available threshold, even as humidity drives heat indices near 110°F [3]. On-chain, traders are locking USDC on Polygon to back conditional tokens, with "98–99°F" emerging as the frontrunner at 41% and "96–97°F" trailing at 20% [1].

Historical context for mid-July in NYC shows that 100°F highs are rare, occurring only once in the last 12 years, which frames why the market is pricing out extreme outliers despite the current roasting conditions [3]. The settlement relies strictly on Wunderground’s daily maximum for KLGA, meaning even a brief spike above 99°F would shift resolution, yet the prevailing forecast caps today at 95°F before rising to 97°F tomorrow [2]. This gap between the 95°F forecast and the 98–99°F frontrunner suggests traders are betting on a late-day surge or a forecast error rather than the baseline expectation.

Key catalysts include the weakening of the high-pressure system after July 16, when a cold front from the west is expected to drop temperatures back into the 80s by July 17 [2]. Traders should monitor real-time updates from AccuWeather and local meteorological bulletins, as the current heatwave is described as the hottest of the summer so far, with nights staying above 75°F and offering little relief [2]. Any deviation in the cold front’s timing or intensity could alter the final recorded maximum, directly impacting the conditional token payouts on the Polygon network.

Sources: 1 · 2 · 3

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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.

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.