Highest temperature in NYC on August 19?

Platform comparison

Market context

On 19 August 2026, the highest temperature recorded at LaGuardia Airport will fall into one of several defined ranges. A YES share in this market pays out if the temperature lands in the specific range the market is pricing; a NO share pays if it lands elsewhere. The resolution hinges on Weather Underground's Daily Observations table rather than their summary figures, a distinction that matters because intraday readings can occasionally diverge from headline highs. This technical specification reduces ambiguity but requires traders to understand which data source Weather Underground prioritises when publishing historical records.

New York's August temperatures typically cluster between 78°F and 88°F, with the city's all-time August high of 102°F set in 1933. Recent decades show mid-August averages around 82–85°F, though heat waves pushing into the low 90s occur roughly every other summer. The current 0% probability on this market suggests traders are pricing in either an unusually cool day or that the specific temperature range being tested falls outside historical norms for that date. Comparing this market against climatological records for 19 August specifically would clarify whether the range is genuinely unlikely or whether market liquidity simply favours other outcomes.

Traders should monitor seasonal forecasts from the National Weather Service and Atlantic hurricane activity in early August, as tropical systems can suppress temperatures across the Northeast. Long-range models become more reliable from mid-July onwards, offering traders a window to reassess probabilities as the settlement date approaches. LaGuardia's elevation and urban heat-island effects mean its readings often run 2–3°F higher than surrounding areas, a factor that influences how broader regional forecasts translate to this specific station's readings.

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 Prediction Market UK, which mirrors the Polymarket order book directly.

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 Prediction Market UK. 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.

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%.