Highest temperature in NYC on July 21?

Platform comparison

Market context

On 21 July 2026, the highest temperature recorded at LaGuardia Airport will fall into one of several predefined ranges. A YES share in this market pays out if the actual peak temperature matches your chosen bracket; a NO share pays if it lands elsewhere. The settlement hinges on historical weather data from Weather Underground, which logs hourly readings across the day. Because the market currently shows 0% implied probability for at least one range, traders are pricing in either extreme confidence in a specific outcome or genuine uncertainty about which bracket will resolve true.

New York's July temperatures typically peak between 82°F and 92°F, though heat waves can push readings above 95°F. LaGuardia's recorded high for 21 July has varied considerably year to year—ranging from the mid-70s during cooler summers to the low 90s during heat events. The 2024 summer saw multiple days exceed 90°F in mid-July, establishing that extreme heat is plausible but not guaranteed for this date. Historical volatility in July weather patterns means no single temperature range dominates with certainty.

The primary catalyst affecting July 2026 temperatures will be the Atlantic hurricane season and jet-stream positioning in early summer. The National Weather Service's seasonal outlooks, typically released in May, will provide initial guidance on whether the Northeast expects above-normal or below-normal heat. Any significant weather pattern shifts—such as a Bermuda high-pressure system stalling over the region—would favour higher ranges. Conversely, tropical systems or cool air masses moving inland could suppress peak temperatures into lower brackets.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Prediction Market UK, which mirrors the Polymarket order book directly.

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

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 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.

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 Prediction Market UK 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.