Highest temperature in NYC on July 7?

Platform comparison

Market context

On 7 July 2026, the highest temperature recorded at LaGuardia Airport in New York City will determine the outcome of a prediction market where the crowd currently assigns only a 3% chance to the temperature reaching the 74–75°F range. This low implied probability stands in stark contrast to the 31.5% probability offered on a parallel contract for the same date on Lines.com, which prices the 74–75°F outcome at $0.32, revealing a meaningful divergence between platforms that traders must scrutinise before committing capital.

Historical data from the early July 2026 heatwave shows LaGuardia hitting 104°F on 2 July, with midnight temperatures reaching a record 94°F, suggesting that while extreme peaks occurred, the recent frontal passage has pushed readings into the mid-70s, making the current 3% market view plausible yet potentially underpriced compared to the 100% certainty of the 70–71°F outcome on the 6 July Polymarket contract. The average July high for the airport typically ranges between 81°F and 99°F, yet the immediate cooling trend following the holiday heatwave frames the current odds as a reaction to transient meteorological shifts rather than seasonal norms.

Traders should monitor the National Weather Service’s daily high-temperature forecasts and any incoming subtropical moisture systems that could disrupt the cooling trend, as recent reports from FOX Weather confirm that record-setting heat lingered unusually late into the night before the frontal passage. The settlement relies exclusively on Wunderground data for LaGuardia, meaning any discrepancy between official NOAA records and the platform’s automated feed could alter the final resolution, so watching for real-time updates on the 7 July forecast is essential for assessing whether the 3% line will converge with the higher analyst consensus seen elsewhere.

Sources: 1 · 2 · 3 · 4 · 5

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

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'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.