Highest temperature in NYC on June 21?

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Active sub-markets

Market context

LaGuardia Airport’s highest temperature on 21 June will be judged on the day’s peak reading at KLGA, and the current 0% YES crowd price points to a market that is effectively saying a qualifying hot outcome is not expected. That is a strikingly low implied probability for late June, when New York commonly moves into its warmest stretch; AccuWeather’s June outlook for New York City shows highs broadly in the 75°F to 88°F range, with an average June high of 83°F, which is consistent with the contract’s upper bands being live but not routine.[4]

Comparable NYC temperature markets have sometimes swung sharply when a heat event is already in place. Forecast commentary published around 21 June described a dangerous heatwave across New York City, with mostly sunny skies, high humidity and temperatures “well above seasonal averages”, and one report said thermometers reached 102°F by midday in the wider metro area.[1] A separate spring forecast piece showed how quickly these contracts can reprice when a hotter-than-normal pattern is locked in, with AccuWeather projecting 95°F to 97°F and coverage highlighting a 101°F “RealFeel” as records came into view.[3] Against that backdrop, today’s 0% YES looks far below the sort of odds usually associated with an active heat alert or a high-confidence upper-90s forecast.

Traders should watch the official forecast and observing-site dependency rather than broader city weather headlines. The settlement source is Wunderground’s daily history for LaGuardia, so the relevant catalyst is whether the airport itself prints a noon-to-midnight high in the chosen temperature bucket, not whether Central Park or social-media reports mention exceptional heat.[1][5] In cross-platform terms, there is a useful divergence to monitor: sportsbook-style weather pricing, if available, tends to anchor to forecasted highs and heat warnings, while prediction-market odds can stay stale until late-model runs or local station forecasts force a repricing. Weather coverage on 21 June pointed to sustained heat and humidity across the Northeast, which is the main dependency for any late move in this contract.[1]

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). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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?

On Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What does it cost to trade on Best Prediction Markets UK?

Zero. Best Prediction Markets UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.