Highest temperature in NYC on July 9?

Platform comparison

Market context

The underlying real-world event is the peak heat recorded at LaGuardia Airport on 9 July 2026, a date that historically marks the height of New York’s summer thermal extremes. Current crowd-implied probability sits at 0% YES, suggesting the market believes the temperature will not reach the specific threshold required for a win, despite the unprecedented heatwave dominating the East Coast this week.

Historical precedents frame this low probability with stark clarity: LaGuardia hit 104°F on 3 July 2026, shattering the 1966 record by 3°F, while Central Park tied its 100°F record the same day[1]. This July 2026 heatwave broke records across a 500-mile corridor that had stood for up to 154 years, killing 29 people in New Jersey and proving the heat was unprecedented for these locations[1]. Yet, the highest ever recorded temperature in NYC was 106°F on 9 July, a specific benchmark that may explain why traders are pricing in a miss for this particular range[5].

Traders must monitor the nightly temperature decay and official Wunderground updates for LaGuardia, as the record-setting heat lingered into the night with midnight readings hitting 94°F, breaking the 2013 record of 93°F[2]. The catalyst to watch is the National Weather Service climatological report, which notes the maximum temperature normal for tomorrow is 86°F with a record of 98°F from 1993[8]. While the heat dome remains intense, the rapid drop from 104°F to 94°F at midnight suggests the 9 July peak may not sustain the threshold needed for a YES outcome, especially given the 0% market pricing[2][10].

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 PolyGram. 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.

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