Highest temperature in London on May 26?

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Market context

On 26 May 2026, the highest temperature recorded at London City Airport will settle into one of several defined ranges. The market uses Wunderground's historical weather data for the station (EGLC) as its sole resolution source, with settlement occurring at 12:00 UTC on that date. The 0% crowd probability suggests traders are either absent from this market or treating it as a placeholder pending clearer range definitions.

London's late May temperatures typically cluster between 18–22°C, with historical highs occasionally reaching 25–28°C during warm spells. The 2022 heatwave saw May peaks near 27°C across southern England, whilst cooler years have recorded maxima around 16–18°C. City Airport, situated on the Thames estuary, tends to register slightly cooler readings than central London due to water proximity and urban heat island effects being less pronounced. These precedents matter because they establish the statistical envelope within which most outcomes will fall; extreme outliers above 30°C or below 12°C are rare but not impossible.

Traders should monitor the UK Met Office's seasonal forecasts and Atlantic pressure patterns in late April and early May 2026, as these drive whether high-pressure systems establish over the British Isles. North Atlantic Oscillation (NAO) indices and jet stream positioning will signal whether continental warm air reaches the south-east. Wunderground's own forecast model updates, published weekly, will narrow uncertainty as the date approaches. Settlement hinges entirely on Wunderground's archived data for that specific station and date; any discrepancies between sources would be resolved against their published record.

Methodology

This page reads Highest temperature in London on May 26? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed for comparison. Every CTA routes to PolyGram, which mirrors the Polymarket order book directly.

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

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.

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.