Highest temperature in London on August 10?

Platform comparison

Market context

The relevant real-world event is the highest air temperature recorded at London City Airport on 10 August 2026, with settlement tied to Weather Underground’s **Daily Observations** table rather than the summary high/low box. That distinction matters because the market resolves off the station log, so late updates or corrections to the table can override an earlier headline figure if they appear before the next day’s first datapoint is published. [1]

The current crowd-implied 0% for YES looks hard to reconcile with London’s August climatology and past extremes. London’s long-run August records show that 10 August can be very warm in exceptional years — Heathrow reached 37.9°C on 10 August 2003, while Kew Gardens hit 38.1°C the same day — but those are outliers, not the norm. More typical London August highs sit in the low-to-mid 20s °C, which is why a specific temperature band outcome usually dominates once forecasts settle. [4][6][9]

For traders, the main catalysts are the day’s forecast revisions and the station’s actual observation schedule, rather than policy or legal developments. On the regulatory side, German GlüStV rules can affect whether residents in Germany may access prediction markets at all, while the US CFTC has asserted broad jurisdiction over event contracts offered to US persons, so venue and user location matter for access. A “no-KYC up to $1,500” model means smaller balances may be usable with lighter identity checks, but it does not remove geoblocking, sanctions screening, or withdrawal controls; in practice, it mainly affects how easily a new account can enter this specific weather market.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This overview of Highest temperature in London on August 10? 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

Do I need to KYC for Is Kalshi Legal in California?

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. Is Kalshi Legal in California exports a full transaction history (CSV/PDF) for tax reporting. In an audit you'll need to present these documents.

Are prediction markets gambling?

Legally unclear in most jurisdictions. Some interpretations classify them as wagering (gambling regulation applies), others as derivatives (financial regulation applies). There's no global precedent specifically for on-chain prediction markets.

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).