Highest temperature in NYC on July 20?

Platform comparison

Market context

On 20 July 2026, the highest temperature recorded at LaGuardia Airport will determine the outcome of a weather contract on Polymarket, where the crowd currently prices the “YES” outcome at 0%. The frontrunner is the 82–83°F range, which holds a 100% implied probability, while outcomes below 69°F sit at 0% [1]. This pricing reflects July’s typical heat in New York City, where daily highs average around 30°C (86°F) and humidity often pushes temperatures higher [2].

Historically, mid-July in NYC rarely dips below 75°F, with LaGuardia frequently recording highs between 80°F and 90°F during warm spells. The current 100% allocation to 82–83°F aligns with these patterns, suggesting traders view cooler outcomes as statistically improbable. Conditional tokens on Polygon, settled in USDC, allow precise exposure to this range without needing to predict the exact degree, focusing instead on bracketed outcomes.

Traders should monitor the National Weather Service’s weekly forecast for NYC and any heat advisories issued ahead of 20 July, as these often signal sustained high temperatures. Wunderground’s historical data for KLGA will be the official resolution source, so real-time updates from that station on the settlement day are critical [1]. No major climate announcements are expected, but sudden shifts in the jet stream or humidity levels could alter the final reading.

Sources: 1 · 2

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Scam? 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.