Highest temperature in NYC on August 18?

Platform comparison

Market context

LaGuardia Airport's highest temperature on 18 August 2026 will be recorded in the Daily Observations table on Weather Underground and resolved against discrete temperature bands. The 1% crowd probability reflects expectation of a moderate summer day in New York, where August highs typically range between 75–85°F. Settlement occurs via USDC against the precise instrumental reading at the station, not the rounded summary figures often cited in weather apps.

August heat in the New York metropolitan area has shown measurable variance over recent decades. The National Weather Service records indicate that extreme heat days—those exceeding 90°F—occur in roughly 15–20% of August days across the region, though LaGuardia specifically tends toward the cooler end of city readings due to proximity to water bodies. The current 1% probability suggests the market is pricing in a cooler-than-typical August day or pricing out tail-risk heat scenarios entirely. Historical August 18th data from prior years shows no exceptional pattern; the date carries no climatological significance that would drive outsized temperature swings.

Traders should monitor National Weather Service forecasts released in the week preceding 18 August 2026, particularly any Atlantic tropical system activity or heat dome positioning over the Northeast. The National Oceanic and Atmospheric Administration's seasonal outlooks, updated monthly, will signal whether summer 2026 tracks warmer or cooler than the 30-year normal. Weather Underground's data feed integrity matters directly to settlement; any station maintenance or sensor recalibration scheduled near the resolution date could affect reading reliability, though such events are typically flagged in advance.

Methodology

This page reads Highest temperature in NYC on August 18? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

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.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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%.