Highest temperature in London on June 1?

Platform comparison

Active sub-markets

Market context

On 1 June 2026, the highest temperature recorded at London City Airport will determine which range this market resolves to, with settlement occurring at 12:00 UTC that day. The resolution data comes directly from Weather Underground's historical records for the EGLC station, eliminating ambiguity around measurement source or methodology. Current crowd pricing at 0% YES reflects either extreme confidence in a specific outcome or minimal trading activity; either way, the market awaits substantive position-taking as the date approaches.

London's June temperatures typically range between 18–23°C, though the city has recorded highs exceeding 30°C during heat waves. The 2022 heatwave saw temperatures reach 40.3°C in parts of Greater London, though City Airport readings tend to run slightly cooler due to proximity to the Thames. Historical June data from the Met Office shows that temperatures above 25°C occur roughly one year in three, providing a baseline for assessing which ranges carry genuine probability mass versus those priced as tail events.

Traders should monitor the UK Met Office and BBC Weather forecasts from late May onwards, as these typically offer ten-day outlooks with reasonable accuracy. Atlantic weather patterns—particularly the position of high-pressure systems and jet stream behaviour—will determine whether continental warm air reaches the southeast. Any significant weather announcements or model shifts in the final week before 1 June could trigger repricing, particularly if forecasts signal either unseasonably warm conditions or cooler-than-average weather. Settlement via USDC on btc-prediction.bet will execute once Weather Underground publishes the official daily high.

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — are listed with their platform attributes, because they operate off-chain and a 1:1 comparison of contract mechanics isn't possible.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, BTC Prediction triggers a quick verification flow that finishes in 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.