Highest temperature in London on July 9?

Platform comparison

Market context

London is currently gripped by an intense heatwave that has pushed daytime highs to 33°C–34°C, but forecasters warn that a dramatic shift to thunderstorms and heavy rain is expected to dominate the city on Thursday, 9 July 2026[3][4]. This unsettled pattern, with clouds blocking the sun and downpours arriving from midday, will likely suppress the peak temperature well below the 33°C threshold required for a "YES" resolution, aligning with the current crowd-implied probability of 0%[3][6].

Historical July data for London typically sees average highs around 23°C, with the warmest day of the month occurring later in July rather than early in the month[10]. While the current heatwave has produced exceptional temperatures peaking at 34°C on Monday, the sudden introduction of storms on 9 July mirrors past instances where rapid atmospheric instability caused temperatures to plummet quickly, making a sustained high of 33°C highly improbable for this specific date[3][4].

Traders should monitor the Met Office's amber heat alerts, which cover London from 9am on 8 July until 9pm on 12 July, and watch for the timing of the thunderstorm front predicted to arrive late on 8 July and continue through 9 July[4]. The primary catalyst the market leans on is the confirmed forecast of scattered thunderstorms and rain expected to dominate London from morning until night on 9 July, which will directly prevent the temperature from reaching the required high[3][6]. No political debates or campaign disclosures are relevant to this weather outcome; the sole driver is the meteorological shift to unsettled conditions.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page tracks Highest temperature in London on July 9? 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.