Highest temperature in London on August 7?

Platform comparison

Market context

London’s highest temperature is the key settlement figure, and the current **0% YES** crowd price implies the market is treating a qualifying reading as effectively impossible. That looks out of step with the live weather picture: AccuWeather’s August forecast for London shows daily highs in the high 60s to upper 70s Fahrenheit, while a contemporaneous forecast said Friday, 7 August, should reach about **26°C** with little rain risk.[1][4] On a cross-platform read, that places the contract below the sort of mid-20s outcome implied by comparable prediction-market pricing, where PolyBet was clustering most probability around **26°C to 27°C** rather than the lower bands.[2]

Historical context also argues against reading a zero as a strong signal that the day will underperform completely. London’s August climate norm is far from cool, with average highs around **73°F** and recent comparable London heat episodes reaching **26.6°C** at Kew Gardens earlier in the summer, showing that the capital can still produce warm outcomes without a formal heatwave.[1][7] Against that backdrop, a 0% YES line looks more like a thin-liquidity price than a robust consensus, especially if the market’s temperature bands are set around the upper-20s Celsius and the eventual Airport reading lands near the forecasted daily high.[2][4]

For traders, the main catalyst is the actual **Weather Underground Daily Observations** entry for London City Airport, not the summary high/low panel, because the contract explicitly settles on the former if they differ. The key dependency is whether the station posts a late-afternoon maximum that falls into the relevant range before the **12:00 UTC settlement window** closes; that matters more here than broader London forecasts, which can diverge by location and timestamp.[2] Recent UK reporting also pointed to a renewed warm spell with temperatures climbing through southern and south-eastern England, which supports the possibility of a higher airport reading if that heat reaches London on time.[13]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on August 7? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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 PolyGram. 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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.