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 market currently prices the “YES” outcome at 0% probability. The frontrunner is the 82–83°F range, which holds a 100% implied probability, suggesting traders are virtually certain the peak heat will fall within that band rather than dip lower or spike higher [1]. This pricing reflects a consensus built on on-chain conditional tokens settled in USDC on the Polygon network, where liquidity has concentrated heavily around the mid-80s Fahrenheit outcome.

Historically, NYC July highs at LaGuardia typically cluster between 80°F and 90°F, with 82–83°F representing a common, moderate summer peak rather than an extreme [2]. The current 0% probability for lower ranges aligns with past data showing that temperatures below 70°F in mid-July are rare anomalies, usually tied to unusual cold fronts or storm systems that have not been forecasted for this period. Traders reading the 100% concentration in the 82–83°F bin should view it as a reflection of seasonal norms rather than a speculative bet on record heat.

Key catalysts include the daily Wunderground temperature report for KLGA, which serves as the official resolution source, and any sudden shifts in regional weather models before the settlement window closes at 12:00 UTC on 20 July [1]. While no specific announcements are pending, traders should monitor the National Weather Service’s hourly forecasts for the Northeast, as unexpected cloud cover or precipitation could alter the peak temperature. The contract’s dependency on a single station’s daily maximum means volatility will hinge entirely on real-time atmospheric conditions rather than broader climate trends.

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

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 UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.

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 Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.