Highest temperature in London on August 6?

Platform comparison

Market context

London’s late-summer temperature is typically more about low-20s Celsius than extreme heat, and the current market is pricing that baseline heavily: the leading outcomes are clustered around **22°C–24°C**, with 22°C and 23°C each the frontrunners in the crowd data.[3] That aligns with published August climate guides for London, which put average daytime highs around the high teens to low 20s rather than the upper 20s.[12] For context, the market’s **0% YES** implied probability is a strong statement of scepticism, but it can be read as a bet against a hotter-than-expected spike rather than a claim that warmth is impossible.

Comparable cases matter because London can still jump well above its seasonal norm when a short-lived warm plume reaches the south-east. UK coverage this summer has already documented notable heat, including London hitting 26.6°C at Kew Gardens and a broader spell that made 2026 the hottest year so far in parts of the UK.[9][14] The benchmark to watch is therefore not the average August pattern but whether the day behaves like a standard mild spell or an outlier driven by synoptic heat. On the current evidence, the market looks anchored to the cooler end of the forecast range rather than to any record-chasing scenario.[1][4]

The key catalyst is the near-term weather forecast for London and any intraday revision to maximum-temperature expectations before the settlement cut-off. News forecasts currently point to a sunny, mild day with a high around **22°C**, which is broadly consistent with the market’s centre of gravity and helps explain why there is little appetite for a higher bracket.[4] Traders will be watching whether updated forecasts, cloud cover, or a stronger-than-expected warm advection shift the day’s peak towards the upper-20s band; absent that, the implied probabilities should continue to cluster around the low-20s outcomes.[3][16]

Sources: 1 · 2 · 3 · 4 · 5

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 6? 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

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.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

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.