Highest temperature in NYC on July 1?

Platform comparison

Market context

The real-world event this market tracks is the peak temperature recorded at New York’s LaGuardia Airport on 1 July 2026, measured in Fahrenheit and resolved via Wunderground. With the crowd-implied probability of a specific high-temperature range sitting at 0% YES, the market currently signals extreme uncertainty or a lack of conviction in any particular outcome, which is unusual for a date with well-documented historical extremes.

Historically, LaGuardia has seen July highs reach 107°F on 3 July 1966, while the average high for early July typically falls between 81°F and 99°F, with overnight lows ranging from 68°F to 83°F[9]. June 2026 forecasts showed daily highs peaking at 99°F, suggesting that early July could follow a similar thermal pattern, though the 0% probability implies traders are either hedging against outliers or awaiting clearer signals[1]. The 100°F record from 2021 remains a credible benchmark for high-temperature scenarios[2].

Traders should monitor the National Weather Service’s daily climatological reports for LaGuardia, which provide real-time temperature normals and record deviations[2]. A key catalyst is the Wunderground historical data feed, which will resolve the market once the 24-hour high is logged for 1 July 2026[5]. Recent forecasts indicate steady temperatures around 91°F with heat indices up to 99°F, suggesting a plausible high-temperature range if conditions remain stable[6]. Programmatic approaches would involve scraping Wunderground’s API at settlement time to capture the official high, then cross-referencing with NWS normals to validate anomalies[8].

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

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.

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.