Highest temperature in London on August 4?

Platform comparison

Market context

London’s recorded high on 4 August will be taken from London City Airport Station, so the market is really a play on the day’s peak air temperature rather than the afternoon average. Recent London forecasts have pointed to a warm but not extreme day, with highs generally around 22-27°C and some outlets flagging rain or thundery showers later in the afternoon, which matters because cloud, breeze and showers can cap the eventual maximum even when the morning starts mild.[3][5][6][14]

The crowd’s 0% YES implies the market is pricing in an outcome outside the listed range bands, but that is hard to square with recent comparable August conditions in London, where long-run averages sit near the low 20s and current seasonal forecasts cluster in roughly the same zone.[1][2][7][15] For context, London’s August profile is typically comfortable rather than hot, so a very low or very high reading would usually need an unusual synoptic set-up, such as persistent rain-cooled air or an unexpectedly strong warm sector.[1][7][13]

From a market-access perspective, this sits in the grey area that matters for European users: German GlüStV rules can restrict access to online gambling-style products if a platform is treated as one, while US CFTC reach is the larger issue for US-based traders because event contracts may fall within commodities regulation depending on venue and structure. A “no-KYC up to $1,500” policy usually means lower-friction access for small balances, but it does not remove age, sanctions, or jurisdiction checks, and it can still be limited by country blocks or verification triggers on withdrawals and higher-volume activity.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This overview of Highest temperature in London on August 4? 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.

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.

Is there a withdrawal cap?

No platform-side cap. You can withdraw any amount provided KYC is complete. SEPA bank withdrawals over €15,000 trigger additional anti-money-laundering checks (statutory obligation for all platforms).