Highest temperature in London on July 5?

Platform comparison

Market context

The underlying real-world event is that London City Airport will record a peak temperature on 5 July 2026, with the market currently pricing a specific 29°C bucket at 0% probability. This zero valuation reflects the immediate weather reality: a wet, blustery pattern is moving into southern England, bringing rain bands and gusty winds that will suppress temperatures to a mild 15–17°C range for the day [4].

Historical data frames this low probability clearly, as July is statistically London’s warmest month with average highs of 23°C, yet recent heatwaves have pushed temperatures above 30°C and even to a record 40.2°C at Heathrow in July 2022 [1][2]. However, the current atmospheric conditions are the direct opposite of a heatwave, with heavy cloud cover and precipitation ensuring the mercury will struggle to reach 20°C, making a 29°C peak virtually impossible under today’s forecast [4].

Traders should watch the Met Office weather warnings and the incoming rain schedule, as the downpour is expected to be heaviest between 6:00 and 9:00 a.m., keeping temperatures firmly in the cool 14–19°C bracket [4]. On-chain mechanics remain standard for Polymarket, with USDC settlements on the Polygon network using conditional tokens, but the fundamental catalyst here is the persistent southerly wind and damp air that will prevent any significant temperature climb [4]. No announcements or schedules will alter this outcome, as the weather system is already locked in to deliver a cool, wet July 5.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on July 5? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.