Highest temperature in London on July 12?

Platform comparison

Market context

London City Airport is currently under mostly cloudy skies with a temperature of 11°C (64°F) and a gentle northeast breeze, conditions that have suppressed any immediate heat spike for today’s high temperature reading [1]. The crowd-implied 0% probability for a high temperature outcome reflects this persistent coolness, as the atmosphere lacks the sustained solar heating required to breach typical July thresholds.

Historically, July in London averages 23°C highs, yet heatwaves frequently push temperatures above 30°C, with the record reaching 40.2°C at Heathrow in July 2022 [6]. While 2026 is forecast to experience at least one sustained scorcher, the current cloud cover and 77% humidity at EGLC suggest the day will fall well below the 30°C mark that would trigger a positive resolution [1][6]. Traders should note that short, sharp afternoon thunderstorms often strike between 15:00 and 17:00, which could further limit temperature peaks if they develop later today [6].

The primary catalyst to watch is the Met Office’s 7-day forecast update, which may clarify if a high-pressure system is approaching to clear the clouds and drive temperatures up [3]. Weather Underground’s daily history page for EGLC will provide the definitive settlement data, so monitor real-time updates for any sudden shifts in cloud cover or wind direction that could alter the day’s maximum [1]. With the settlement window ending at 12:00 UTC on 12 July 2026, the next few hours of observation are critical for confirming whether the day remains cool or unexpectedly warms.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on July 12? 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

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 Prediction Today. 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.

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.

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.

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.