Highest temperature in London on July 21?

Platform comparison

Market context

On 21 July 2026, the highest temperature recorded at London City Airport Station will determine the settlement range for this market. The resolution source is Wunderground's historical weather data for that specific location and date, with temperature measured in degrees Celsius. The current crowd probability of 1% suggests traders expect an outcome in a particular range—likely one of the upper or lower extremes available in the market's resolution brackets.

London's July temperatures have historically ranged between 20°C and 28°C, with extreme highs above 30°C occurring roughly once per decade. The record high for London in July stands at 36.5°C (recorded in 2022), though City Airport's microclimate—influenced by proximity to the Thames and urban heat effects—typically records slightly lower maxima than central London stations. The 1% probability reflects either a very narrow or very wide temperature band being priced, depending on the available resolution categories. Comparable July forecasts from the Met Office and historical volatility suggest most outcomes cluster between 22°C and 26°C, making extreme ranges less likely.

Traders should monitor seasonal weather patterns emerging in late June 2026 and any Atlantic pressure systems forecast to influence the UK in early July. The Met Office's long-range outlook, typically issued in early July, will provide directional guidance on whether high-pressure systems or Atlantic fronts dominate. City Airport's specific measurement protocols—taken at standard height and time—mean local conditions matter; cloud cover, wind direction, and urban heating all influence the final recorded figure. Settlement occurs at 12:00 UTC on 21 July, so the highest temperature recorded across the entire calendar day determines the outcome.

Methodology

This overview of Highest temperature in London on July 21? reviews the four comparable platforms from a regulatory perspective: which is accessible in your jurisdiction, where KYC kicks in, how the platform is classified by your country of residence. Live probability is the Polymarket mid; comparison columns show regulatory status, KYC thresholds and settlement options for each platform.

Resolution & payout

On Polymarket, resolution runs on-chain via UMA Optimistic Oracle. USDC payout is instant and automatic, with no KYC. Tax treatment depends on your jurisdiction — in the US, gains are usually ordinary income; in the UK, often capital gains. Consult a tax professional for your situation.

FAQ

Is Polymarket legal in my country?

Polymarket is geo-blocked in the US/UK/EU. Actual usage via the Polymarket interface is not possible there. The legal status itself varies — many countries treat prediction markets as a gray area. Polymarket Legal UK has a different geo footprint.

Do I need to KYC for Polymarket Legal UK?

Not for lifetime trading volume under $1,500. Above that threshold, a quick KYC flow kicks in — ID, selfie, approximately 5-10 minutes. The threshold matches FATF travel standards for unregulated crypto platforms.

How are winnings taxed?

Tax treatment varies by jurisdiction. In most countries, prediction market gains are treated as ordinary income or capital gains. We cannot provide tax advice — consult a tax professional for your specific situation.

Can I trade anonymously?

Pseudonymously, yes — up to the KYC threshold. Polymarket Legal UK stores an email address and wallet addresses rather than a legal name. Over $1,500 lifetime volume triggers KYC, after which identity is no longer anonymous.

What happens during a tax audit?

You're responsible for documenting your trades. Polymarket Legal UK exports a full transaction history (CSV/PDF) for tax reporting. In an audit you'll need to present these documents.