Highest temperature in NYC on July 12?

Platform comparison

Market context

A dangerous heat dome has locked over the Northeast for the past 48 hours, pushing New York City temperatures to record-breaking levels. On July 10, LaGuardia Airport hit 104°F, the highest ever recorded for that date, while overnight lows refused to drop below 85°F [4][6]. This extreme warmth has driven the crowd-implied probability for the 82–85°F range to near zero, as traders now expect the July 12 high to land significantly higher, likely in the 84–85°F bracket or above [1].

Historically, July 12 in New York averages 85.1°F, with the all-time record for the date standing at 99°F [5]. The current 0% probability for the lower range reflects a market that has already priced in the ongoing heatwave, treating the 84–85°F outcome as the new baseline rather than an outlier. With the heat peak expected to sustain through Friday and Saturday, the 82–83°F range has been effectively discarded by the collective view [6].

Traders should monitor the National Weather Service’s heat alert updates and the real-time readings from LaGuardia Airport, as the settlement source is Wunderground’s daily high for KLGA [2][4]. The heat dome’s persistence is the primary catalyst; if the dome weakens before Sunday afternoon, temperatures could dip toward the average, but current forecasts suggest continued scorching conditions with highs potentially reaching 96°F [3]. Watch for any official announcements on heat advisory extensions, which could confirm the market’s bias toward the upper ranges.

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 Prediction Today. 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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.