Highest temperature in NYC on July 3?

Platform comparison

Market context

The real-world event driving this market is the highest temperature recorded at LaGuardia Airport on 3 July 2026, measured in degrees Fahrenheit. Current crowd-implied probability for the "YES" outcome sits at 0%, yet Polymarket data shows the leading outcome is "100-101°F" at 97%, suggesting the market expects extreme heat despite the initial zero probability signal[1]. Historically, LaGuardia recorded its all-time high of 107°F on exactly 3 July 1966, a benchmark that frames how traders should interpret current volatility[9]. Recent heat waves have pushed LaGuardia to 104°F, surpassing its 1966 daily high of 101°F, confirming that 100°F+ is a credible threshold for this date[7].

A power-user approaching this programmatically would monitor real-time dependencies from Wunderground, the official resolution source, rather than relying on static forecasts[1]. Key catalysts include the ongoing heat wave updates, with LaGuardia hitting 104°F just days prior, and the record-breaking warmest midnight of 94°F recorded recently, indicating sustained thermal pressure[7][5]. Traders should watch for announcements from the National Weather Service regarding temperature thresholds, as LaGuardia’s July 2026 forecast already projects highs up to 99°F, with overnight lows between 68°F and 83°F[6]. The 97% probability assigned to "100-101°F" reflects a strong consensus that this specific range will contain the day’s peak, making it the primary target for conditional order strategies[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in NYC on July 3? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi Fees, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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 Fees 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.