Highest temperature in NYC on August 7?

Platform comparison

Market context

The real-world event is the highest temperature logged at LaGuardia Airport on 7 August, with settlement tied to the Weather Underground daily observations rather than the headline day-high figure. That matters because the contract can turn on the final observation table entry and any late update before the next day’s first datapoint, so a crowd price of **0% YES** implies traders are effectively treating an in-range resolution as impossible even though the market is still open to a weather-based printout rather than a discretionary judgement.

Historically, New York City summer highs often cluster in the upper 80s to low 90s Fahrenheit, and the available August 2026 pricing elsewhere has already been centred around that band. Polymarket’s own event page for the same date showed the biggest bucket at **90–91°F** and the next at **88–89°F**, while AccuWeather’s monthly view put 7 August at **84°F / 71°F** and 8 August at **87°F / 73°F**, underscoring how sensitive these contracts are to local station specifics and intraday revision risk.[3][1] Extreme-weather context also matters: New York City reached **100°F** earlier in the 2026 summer, so the range of possible outcomes remains wide enough that a single hot afternoon can materially change the settlement bucket.[5]

For traders, the key catalysts are the late-day temperature peak, any convective showers that suppress the maximum, and the eventual publication of the next day’s first observations on Weather Underground, which locks the result. In on-chain terms, this is a simple USDC-settled binary outcome, so the main market-moving inputs are meteorology rather than crypto beta, though BTC and ETH risk appetite can still affect secondary liquidity and spread quality across prediction venues. The most useful external check is the station-level history page for LaGuardia and the local forecast guidance from the National Weather Service; both can shift intraday as moisture, cloud cover, or thunderstorm timing changes the realised high.[4][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

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%.