Highest temperature in NYC on August 9?

Platform comparison

Market context

The event is the **highest temperature recorded at LaGuardia Airport on 9 August 2026**, and the market settles on the range that contains that peak reading from Weather Underground’s **Daily Observations** table, not the summary “Day High & Low” figure. In plain terms, a **YES** share pays if the final official reading lands in the contract’s specified temperature bucket; a **NO** share does not, and the crowd-implied probability is the market’s live estimate of that bucket’s chance.

For context, LaGuardia had already posted a **91.0°F** maximum on 7 August in one August climate monitor, while Weather Underground’s historical Manhattan page showed a LaGuardia report of **88.0°F** at 1:51 pm EDT on 9 August with a 6-hour high of **89.1°F** at that time. That points to a warm but not necessarily extreme day, which helps explain why traders often focus on whether the airport can push into the low 90s rather than simply whether it stays hot. The market’s 0% YES price suggests either that the currently leading bucket is elsewhere or that liquidity is too thin to assign meaningful odds.

The main catalysts are the **final hourly observations** from LaGuardia and the moment Weather Underground rolls over to the next day, because this contract resolves only after the full set of observations for 9 August is available. Traders usually watch short-range forecasts, heat advisories, and any change in wind, cloud cover, or rain timing, since those can shift the afternoon peak by a degree or two. The National Weather Service had an updated forecast page for the LaGuardia area showing **78°F** early on 9 August with a **heat index of 80°F**, which is the sort of information that can move expectations before the final daily maximum is locked in.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in NYC on August 9? 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

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.

UK Frequently Asked Questions

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 Market 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.