Highest temperature in NYC on July 23?

Platform comparison

Market context

Polymarket is currently pricing the **80–81°F** band as the clear favourite at **72%**, with **82–83°F** next at **19%**, so the contract is leaning towards a fairly ordinary late-July maximum rather than a sharp temperature spike. Because settlement uses the **highest temperature recorded at LaGuardia Airport Station** on 23 July and pays out through **USDC on Polygon** via **conditional tokens**, traders are really pricing one specific airport observation rather than a broad New York City feel.[1]

That 72% print is easier to read against the city’s summer volatility: New York can swing quickly from comfortable highs into heatwave territory, but the market’s current centre of gravity implies the street expects a peak that stays in the low 80s rather than pushing into the upper 80s or 90s. The earlier July heatwave coverage showed how quickly forecasts can shift when an air mass stalls over the region, with a run of near-100°F expectations later easing back towards more normal summer values as storms and humidity changed the setup.[2]

The main catalysts for a trader are the **final local forecast** for Queens and the airport’s realised afternoon high, since a few degrees either side of 80°F can move the result into a different band. The key dependency is the **Wunderground LaGuardia history page** that the market uses for settlement, so the live reading there matters more than headlines about New York temperatures in general. In practice, a shift in cloud cover, sea-breeze timing, or thunderstorm coverage before the afternoon peak is what can still push the outcome away from the current frontrunner.[1][2]

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

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

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

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.