Highest temperature in London on June 17?

Platform comparison

Active sub-markets

Market context

On 17 June 2026, London City Airport's weather station will record a daily high temperature. The settlement hinges on identifying which temperature band contains that peak reading, measured in Celsius and sourced from Wunderground's historical database. The 0% crowd probability suggests traders are either absent from this market or treating it as a placeholder pending liquidity injection—a common pattern for weather markets that lack early deposit activity on UK payment rails.

Historical June temperatures at London City Airport cluster between 18–24°C on average, with occasional spikes to 26–28°C during warm spells. The 2022 heatwave pushed readings above 30°C, but such extremes occur roughly once per decade. Current market inactivity reflects both the 18-month settlement window and friction in the deposit funnel; traders using Klarna or SEPA transfers often wait until closer to event dates before committing capital, particularly for niche weather outcomes with thin order books.

The Met Office's seasonal outlook and any Atlantic weather pattern shifts in spring 2026 will shape trader conviction. Early-season forecasts typically emerge 3–4 months prior; traders monitoring the UK's winter-to-spring transition should watch for official guidance on summer temperature anomalies. Book depth will likely accelerate in May 2026 as settlement approaches and payment onramps see higher throughput, converting passive interest into active positions across temperature bands.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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?

On Polymarket Klarna UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

What does it cost to trade on Polymarket Klarna UK?

Zero. Polymarket Klarna UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.