Highest temperature in London on July 8?

Platform comparison

Market context

The highest temperature recorded at London City Airport on 8 July 2026 is the real-world event this contract resolves to, with the current crowd-implied probability of hitting any specific high range sitting at 0% for the "YES" outcome. On Polymarket, this contract trades today with USDC on the Polygon network, where conditional tokens reflect the market’s near-zero confidence in the event occurring as defined, despite historical precedents suggesting summer peaks often exceed 30°C in the capital.

Historically, July in London frequently sees peak temperatures between 29°C and 32°C, as seen in the 2026 UK heatwaves where Lingwood recorded 37.7°C during the second heatwave starting 19 June[8]. Comparable data from AccuWeather forecasts July 2026 highs at London City Airport ranging from 71°F to 87°F (21.7°C to 30.6°C), with average highs near 26°C[7]. The Met Office also projects a 21°C low for 8 July under clear skies, implying daytime highs could reach 30°C or more[1].

Traders should monitor the Met Office and ECMWF ensemble runs for shifts in the 8 July forecast, particularly any announcements regarding the third heatwave’s progression, which is already impacting transport and NHS services as of 7 July[5]. A key dependency is the Wunderground data feed, which will settle the market based on the highest temperature recorded for all times on that day at London City Airport[6]. Recent news confirms the third heatwave is active, making it a critical catalyst for temperature spikes that could alter the 0% probability[5].

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 PolyGram, which mirrors the Polymarket order book directly.

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 PolyGram. 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 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 PolyGram 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.