Highest temperature in London on August 19?

Platform comparison

Market context

The market concerns the highest temperature recorded at London City Airport on 19 August 2026, with settlement based on Weather Underground's Daily Observations table rather than summary figures. The 0% crowd probability reflects the market's current state ahead of the two-year settlement window.

London's August temperatures have historically ranged between 18°C and 28°C, with extremes occasionally breaching 30°C during heat waves. The Met Office records show that temperatures above 25°C occur in roughly 40% of August days in the capital, whilst readings exceeding 32°C remain rare events concentrated in exceptional years. August 2022 saw a peak of 40.3°C across parts of southern England, though London City Airport recorded lower figures. These historical patterns suggest the market's current pricing reflects baseline expectations rather than anticipation of extreme heat.

Traders should monitor seasonal climate forecasts released by the Met Office in the months preceding August 2026, which typically provide guidance on temperature anomalies three to four months ahead. The North Atlantic Oscillation and sea surface temperatures in the Atlantic will influence whether high-pressure systems establish over the UK during mid-August. Recent summers have shown increasing variability; the Met Office's long-range outlooks from spring 2026 onwards will signal whether conditions favour above-normal or below-normal temperatures. The specific resolution methodology—using Daily Observations rather than Day High & Low summaries—means traders should familiarise themselves with Weather Underground's data collection practices at London City Airport, as discrepancies between reporting methods have occasionally affected similar markets.

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in London on August 19? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

UK Frequently Asked Questions

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

Are political prediction markets legal in my country?

It varies. They sit in legal gray areas in most jurisdictions. Polymarket is geo-blocked from US/UK/EU; some broker frontends have a different geo footprint. Trade only with capital you can afford to lose, and only if you understand the legal status in your jurisdiction.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.