Highest temperature in NYC on July 19?

Platform comparison

Market context

The settlement hinges on the single highest temperature reading at LaGuardia Airport on 19 July 2026, measured in Fahrenheit and resolved via Weather Underground's historical records. The 0% crowd probability suggests either extreme confidence in a specific temperature band or minimal trading activity on this particular contract. July in New York typically sees daily highs between 82–88°F, with occasional peaks above 90°F during heat waves. The market's structure requires traders to predict which discrete range will capture the day's maximum, rather than a precise figure.

Historical July temperatures at LaGuardia show considerable year-to-year variance. The airport's records indicate that temperatures exceeding 95°F occur roughly once per decade in mid-July, whilst readings below 75°F are rare. The 2019 heat wave pushed readings to 92°F on 19 July itself, providing a recent comparable case. Traders assessing probability distributions should reference the National Weather Service's 30-year climate normals for New York, which establish a median high of 84°F for this date, with standard deviation around 5–6°F.

The National Oceanic and Atmospheric Administration's extended forecasts, typically issued 8–14 days ahead, will provide the most actionable catalyst for position shifts. Atlantic tropical systems or Bermuda High positioning in early July could materially alter expected conditions. Current sportsbook weather derivatives show minimal divergence from historical climatology, suggesting the market's zero probability reflects either a settlement range positioned well outside the climatological envelope or insufficient liquidity to establish meaningful odds.

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 Best Prediction Markets 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.

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