Highest temperature in London on July 12?

Platform comparison

Market context

On 12 July 2026, the market tracks the highest temperature recorded at London City Airport, with settlement based on the day’s peak reading in degrees Celsius from Wunderground. In prediction markets, a YES share pays out if the event occurs as defined, while a NO share pays out if it does not; here, the 0% crowd-implied probability for YES suggests traders believe the specific temperature range in question is virtually impossible given current conditions.

Historical July data for London City Airport shows average highs around 22°C (72°F), with recent heatwaves pushing peaks near 35°C, as seen on 9 July 2026[4]. However, today’s actual high is 29°C with cooling signals including potential thunderstorms and falling pressure, which aligns with the market’s near-zero confidence in extreme heat outcomes for this specific range[4][7]. The average July high remains modest, making outlier extremes less likely without sustained atmospheric drivers.

Traders should monitor the Met Office’s 7-day forecast updates for London City Airport, which include temperature, rain, wind, and UV warnings[3]. Key catalysts include any sudden shifts in southerly wind patterns or humidity levels, currently at 88%, which could suppress peak temperatures[7]. With no major heatwave announcements scheduled and cooling trends emerging, the market’s current pricing reflects these dependencies accurately.

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 Prediction Market UK, which mirrors the Polymarket order book directly.

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.

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