Highest temperature in London on July 26?

Platform comparison

Market context

Polymarket is pricing this London airport temperature contract with **26°C** as the frontrunner at 29% and **24°C** close behind at 25%, while the crowd has assigned **0%** to the YES side in the current framing. For a user trading on the contract, the relevant asset is not the weather itself but a set of conditional tokens on Polygon settled in USDC, where the payout depends on the highest reading at London City Airport Station before the market’s settlement window closes. Shares in the correct temperature bucket redeem for $1, so the live price is the market’s view of where the day’s top reading will land, not a forecast of any single afternoon snapshot.[1]

The historical context points to a July distribution that is usually centred well below extreme heat, with averages commonly in the low-to-mid 20s °C and occasional hotter spikes when high pressure builds over southern England.[4] That makes the current clustering around 24–26°C easy to read as a “normal summer day versus brief warm surge” market rather than a true heatwave bet. Recent commentary has also shown how quickly London temperature expectations can shift when the Met Office changes its view on the longevity of warm spells, which is why even a late-day move in forecast highs can matter more than the opening price suggests.[2]

For traders, the main catalysts are the day’s official forecast updates, any change in cloud cover or shower risk over London, and the actual observations at London City Airport as the session progresses. Because the market resolves to the highest temperature recorded on that station’s Wunderground history page, the key dependency is whether the peak happens before the settlement cut-off and whether a late-afternoon uptick beats the earlier high.[1] In practice, that means the contract can reprice on routine forecast refreshes, not just on major weather news.[1][2]

Sources: 1 · 2 · 3 · 4

Methodology

We track Highest temperature in London on July 26? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

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.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.