Highest temperature in London on June 26?

Platform comparison

Active sub-markets

Market context

The real-world event driving this market is the highest temperature recorded at London City Airport on 26 June 2026, measured in degrees Celsius and resolved via Wunderground data. With the current crowd-implied probability of 0% for a “YES” outcome, the market suggests traders believe the temperature will fall outside the defined range, likely due to expectations of cooler conditions or a mismatch in the range boundaries.

Historically, late June in London has seen highs ranging from 21°C to 35°C, with 26 June 2026’s settlement window closing at midday UTC. Comparable cases include Kew Gardens recording 26.6°C on 24 June 2026 as the hottest day so far this year [3], while London City Airport itself hit 35.7°C on 24 June [6]. These figures frame the current 0% probability as potentially conservative, given recent heat trends and the airport’s exposure to urban warming.

Traders should monitor Met Office forecasts for 26 June, particularly any announcements of heatwaves or cold fronts, and check Wunderground’s live hourly updates as the day progresses. The German GlüStV and US CFTC regulatory frameworks do not directly restrict this market, but the “no-KYC up to $1,500” clause enhances accessibility for retail participants, allowing broader participation without identity verification. A recent Sky News report confirms 26.6°C was recorded in southwest London on 24 June, reinforcing the likelihood of elevated temperatures [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on June 26? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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 PolyGram, 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.

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 PolyGram?

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