Highest temperature in London on July 10?

Platform comparison

Market context

On 10 July 2026, London City Airport will record its peak temperature for the day, a single data point that determines the settlement of this on-chain contract. The market currently prices the "YES" outcome at 0%, reflecting a near-zero probability that the temperature will fall into the lowest resolution range, while the frontrunner is 29°C at 39% and 30°C at 29%[3]. Traders operating on Polygon with USDC should note that conditional tokens are locked against these specific temperature brackets, with resolution dependent on the first Wunderground data point published for this date[3].

Historical July averages for London hover between 23°C and 24°C, yet the 2022 heatwave shattered expectations with a peak of 29.1°C in London on 16 July[6]. While the absolute record for London stands at 40.2°C at Heathrow, London City Airport typically records slightly lower extremes due to its urban location and proximity to the Thames[7]. The current probability distribution suggests the market is pricing a warm day consistent with the 2022 anomaly rather than a standard summer average, framing the 0% "YES" price as a logical dismissal of cold outliers[3].

Key catalysts include the Met Office daily forecast, which currently predicts a maximum of 35°C with a high of 27°C for the day[4], and the southerly wind flow bringing 88% humidity[5]. Traders must monitor the 08:00 UTC update and the subsequent hourly readings, as the resolution source requires the first data point for 10 July to be published before settlement occurs[3]. The BBC forecast indicates sunny conditions with a high of 32°C, reinforcing the likelihood of temperatures clustering around the 29°C–30°C range rather than the lowest bracket[5].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on July 10? 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

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

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK 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.