Highest temperature in London on July 20?

Platform comparison

Market context

The market tracks the highest temperature recorded at London City Airport on 20 July 2026, with the current crowd-implied probability for any outcome sitting at 0% YES, indicating the event has already resolved as a loss. Polymarket data confirms the market is closed, with the final outcome settling at 72–73°F (approximately 22–23°C), a range that did not match the specific contract terms held by traders betting on higher thresholds [1]. This resolved result aligns closely with Met Office forecasts for the period, which projected a maximum daytime temperature of 25°C for London City Airport, suggesting the actual reading fell just within the lower bracket of typical mid-summer variability [3].

Historical July temperatures in London frequently oscillate between 20°C and 28°C, making the 72–73°F resolution a statistically common, though not extreme, outcome for this station. The 0% probability assigned to the contract prior to settlement reflects the market’s accurate calibration against these historical baselines, where days exceeding 24°C are less guaranteed than days hovering near 22°C [1]. Unlike sportsbook lines that might offer dynamic odds on live weather events, this prediction market locked in a static probability that proved correct once the Wunderground data was published, highlighting the divergence between real-time betting platforms and resolved prediction contracts [1].

Traders reviewing similar weather contracts should monitor the Met Office’s daily maximum temperature bulletins and Wunderground’s hourly archives for the specific station, as these are the definitive resolution sources [2][3]. No future catalysts exist for this specific date, as the settlement window ended on 2026-07-20T12:00:00Z, and the final data is now immutable. The absence of any active trading or analyst consensus updates underscores that this contract is purely a historical record, offering no forward-looking insight for future July 20 markets [1].

Sources: 1 · 2 · 3

Methodology

This page reviews Highest temperature in London on July 20? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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 Best Prediction Markets. 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.

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