Highest temperature in London on August 3?

Platform comparison

Market context

London’s reading will be set by the highest temperature logged at London City Airport, so the key question is whether the city gets a broadly warm summer day or a sharper late-morning spike that can push the top of the range higher. The market is currently pricing a very low chance of an extreme outcome, with the crowd leaning heavily towards the low-30s rather than anything much hotter.[1]

That framing matters because London summer temperatures usually cluster around the low to mid-20s Celsius, while the city’s recent warm spells have tended to top out in the high-20s or low-30s rather than deliver sustained extreme heat. The current implied distribution suggests traders are treating this as a standard August warmth case rather than a heatwave breakout, which is consistent with the way London outcomes have historically been read when forecasts call for sunny, settled conditions rather than imported hot air.[2][9][10]

The main catalyst is the forecast path into the airport station: changes in cloud cover, wind direction, and the timing of any sunny intervals will matter more than the daily mean. Traders will usually key off Met Office updates and London-focused weather reports, because the market’s settlement source is a station-specific high rather than a city-wide average.[1][11] If a brief surge in temperatures appears in the morning forecast, that can move the top-end range quickly; if conditions stay mixed, the centre of gravity remains around the market’s current low-30s consensus.[1][14]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page tracks Highest temperature in London on August 3? across four political prediction venues. Live odds come from the Polymarket order book (the deepest political prediction-market book). Kalshi is the CFTC-regulated US alternative, Betfair the established UK sports-exchange with politics markets, Manifold the open play-money variant. For users geo-blocked from Polymarket directly, brokers like Trump Prediction provide a 0%-fee route into the same order book.

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.

FAQ

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.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Trump Prediction route into the same order book at 0% fees.

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.

Which political events have the biggest volume?

US Presidential election, party nominations (DNC/RNC), Senate majorities, individual state outcomes (Pennsylvania, Michigan, Wisconsin), and major European elections. Peak markets reach $50-500M per event.