Highest temperature in London on July 31?

Platform comparison

Market context

London City Airport’s top reading for 31 July will be decided by the day’s warmest Celsius high on the Wunderground record for EGLC, and the market is currently pricing **0% YES**, which makes the listed outcome a deep underdog. In handicap terms, that leaves the consensus firmly against a meaningful heat spike, so any value would need to come from a late-day surge or an official reading that runs hotter than the broad London model consensus. Historical context argues for caution: London’s extreme July highs are real but uncommon, with Heathrow hitting 37.8°C on 31 July 2020 and the all-time UK maximum now standing at 40.3°C at Coningsby in July 2022.[2][6][13]

For traders, the main catalyst is the actual afternoon temperature profile at the airport rather than a headline city forecast, because the settlement source is station-specific and uses the day’s maximum, not the midday reading. In recent UK heat episodes, south-east England has reached the low-to-mid 30s Celsius when the broader pattern has been hot, with the BBC reporting conditions in England and Wales lifting into the upper 20s to lower 30s and some southern spots touching 35°C.[16] That means the favourite remains a cooler band unless London is already embedded in a heatwave, while the contrarian angle sits with a late warming trend or an airport-specific peak that beats nearby London benchmarks such as Heathrow’s 37.8°C and Kew’s 37.3°C from the 2020 event.[2][4]

Sources: 1 · 2 · 3 · 4 · 5

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 Who Will Win 2026, which mirrors the Polymarket order book directly.

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

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.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.