Highest temperature in NYC on August 19?

Platform comparison

Market context

The market concerns the highest temperature recorded at LaGuardia Airport on 19 August 2026, with resolution determined by Weather Underground's Daily Observations table rather than summary figures. The crowd currently assigns 0% probability to the YES outcome, suggesting consensus scepticism about whether temperatures will reach a particular threshold on that date. LaGuardia's August average high sits around 27°C (81°F), though the station regularly records readings above 30°C (86°F) during summer heat waves. Historical data from the past two decades shows August 19th has produced highs ranging from 22°C to 32°C, with no consistent pattern favouring extreme heat on that specific date.

The 0% implied probability reflects the market's baseline expectation rather than any meteorological certainty. August in New York typically brings humid, warm conditions, but predicting a precise day's temperature two years ahead remains inherently uncertain. Traders should monitor long-range climate forecasts released closer to summer 2026, particularly any signals from the National Weather Service regarding Atlantic hurricane activity or heat dome formation patterns that could influence northeastern US temperatures. Recent summers have shown increased frequency of days exceeding 32°C in the region, though this offers limited predictive value for a single date. The resolution mechanism's reliance on Weather Underground's Daily Observations table rather than official NOAA records introduces a minor technical dependency worth noting, though discrepancies between sources are typically negligible for temperature readings.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Who Will Win. 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%.