Highest temperature in London on July 20?

Platform comparison

Market context

The highest temperature recorded at London City Airport on 20 July 2026 has already been finalized, with data confirming the day did not reach the threshold required for a “Yes” outcome. The market has resolved to “No”, as the peak temperature fell within the 72–73°F (approximately 22–23°C) range, well below any extreme heat scenario that would trigger a positive resolution [1].

Historically, mid-July in London rarely produces temperatures exceeding 30°C, and the last instance of such heat occurred during the 2022 heatwaves, when readings briefly hit 40°C at Heathrow but remained lower at City Airport. Comparable years like 2023 and 2024 saw maximums around 26–28°C, reinforcing why the crowd-implied probability for higher ranges was effectively zero before settlement [2].

With the settlement window closed and Wunderground data confirmed, there are no further catalysts to monitor. Traders should note that resolution sources like Wunderground finalise daily records shortly after midnight UTC, meaning no new declarations, debates, or campaign-finance disclosures can influence this outcome. The market’s leaning was always on historical climatology rather than political or economic events, given its weather category and fixed date [1].

Sources: 1 · 2

Methodology

This page tracks Highest temperature in London on July 20? 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 Election Predictions UK 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

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.

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.

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.