Highest temperature in NYC on July 23?

Platform comparison

Market context

The outcome hinges on the highest reading recorded at LaGuardia Airport on 23 July, so traders are really positioning around the day’s peak temperature rather than the evening close. For a programme-driven setup, the practical inputs are the airport observations on Wunderground, with the market settling to the Fahrenheit bucket that contains that day’s maximum; that makes intraday updates, rather than end-of-day headlines, the key signal to poll. At the time of writing, the crowd is heavily concentrated in **80–81°F**, with **82–83°F** the main alternative, which implies the market is pricing a fairly ordinary summer peak rather than a major heat event.[1]

The historical framing is straightforward: NYC summer highs often cluster in the low-to-mid 80s, but brief heat spikes can push airport readings higher when a hot air mass, strong sun and light wind line up. The current **0% YES** crowd-implied probability for the market title should not be read as a forecast of the weather itself; it is a by-product of how the market is structured and priced, and a power user would typically model this by mapping forecast highs into the settlement buckets and then updating as the observed airport maximum comes in through the day.[1]

For catalysts, watch the short-range forecast cycle, any heat advisories, and whether cloud cover or a sea-breeze regime caps the early-afternoon maximum before the airport sensor can print a higher value. Recent reporting has pointed to an intense New York heatwave in early July, with forecasters warning of 100°F conditions and oppressive humidity, which is useful context because markets like this can reprice quickly when guidance shifts from a broad heat pattern to a more local, lower-ceiling coastal setup.[2]

Sources: 1 · 2 · 3

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi Fees, which mirrors the Polymarket order book directly.

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.

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'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.