Highest temperature in London on July 3?

Platform comparison

Market context

The real-world event this market tracks is the highest temperature recorded at London City Airport on 3 July 2026, measured in degrees Celsius. In prediction markets, a YES share means you believe the outcome will fall within a specific temperature range, while a NO share means you believe it will not. Currently, the crowd-implied probability for a YES outcome is 0%, suggesting traders are virtually certain the temperature will not hit the range being offered, likely because the expected peak is far lower than the threshold.

Historical data frames this near-zero probability clearly: London’s average July daily maximum sits between 23°C and 24°C, with the highest recorded temperature on 3 July landing exactly at 26°C [2]. Recent forecasts for July 2026 at London City Airport show daily highs ranging from 71°F to 87°F (roughly 22°C to 31°C), but the average high remains modest [6]. Even during this July’s heatwave, London’s peak reached 32°C at Heathrow, not City Airport, indicating location-specific variability [9]. Given that 26°C is already the historical peak for this date, a range implying significantly higher temperatures would indeed be highly improbable.

Traders should monitor daily weather bulletins from the National Weather Service for London City Airport and Wunderground’s real-time updates, as these are the official resolution sources [3]. Any sudden shift in the Met Office’s forecast for a heat dome over southeast England could alter expectations, though no such announcement has been made yet. The settlement window closes at 12:00 UTC on 3 July 2026, so the final reading will be the maximum temperature recorded at any time on that day [4]. Until a confirmed heatwave is forecast for City Airport specifically, the 0% probability remains well-anchored in historical norms.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Market UK. 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.

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.

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.

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.