Highest temperature in NYC on July 3?

Platform comparison

Market context

The underlying real-world event is that LaGuardia Airport in Queens hit 104°F on 3 July 2026, surpassing its daily high of 101°F from 1966, as a severe heat dome boiled the East Coast[7]. This extreme reading directly contradicts the current crowd-implied probability of 0% for the "Highest temperature in NYC on July 3?" market resolving to the 100–101°F range, which Polymarket users are pricing at 97% confidence[2]. The on-chain mechanics on Polygon, settled in USDC via conditional tokens, mean this discrepancy represents a significant arbitrage opportunity for traders who can verify the Wunderground resolution source before the settlement window closes on 2026-07-03T12:00:00Z.

Historical precedents frame how to read this current probability, particularly the record-breaking midnight temperature of 94°F at LaGuardia just before this event, which shattered the 2013 record of 93°F[1]. Such sustained heat, with overnight lows rarely dipping below 83°F in July 2026, creates a thermal baseline that pushes daily highs well beyond the 100°F threshold, making the market's 0% probability for the 100–101°F outcome appear fundamentally misaligned with the observed data[9]. The 104°F peak recorded at LaGuardia confirms that the heat dome was not merely a forecast anomaly but a realised physical event, rendering the current pricing of the 100–101°F contract as a statistical error rather than a rational hedge.

Traders should monitor the official Wunderground hourly logs for LaGuardia Airport, as the resolution source explicitly relies on the highest temperature recorded for all times on this day[1]. The catalyst to watch is the National Weather Service time-series data, which already logged a maximum of 100°F at 5:20 pm on 3 July, corroborating the extreme heat narrative[4]. Recent news from Fox Weather confirms that holiday travel surges coincided with this record heat, suggesting that the airport's exposure to the heat dome was maximised during peak operational hours, further validating the likelihood of temperatures exceeding 101°F[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in NYC on July 3? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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.

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