Highest temperature in London on July 6?

Platform comparison

Market context

The underlying event is the peak temperature recorded at London City Airport on 6 July 2026, a date historically prone to summer heat spikes. Current crowd-implied probability of 0% for the highest band suggests the market expects temperatures to stay well below extreme thresholds, yet this contradicts established climatic patterns. Met Office data confirms London’s average July high is 23°C, with frequent heatwaves pushing readings above 30°C, and the 2022 record of 40.2°C at Heathrow remains a stark benchmark for potential extremes [1][2]. Recent forecasts for 5–7 July 2026 indicate a significant heat burst with temperatures climbing to 32°C by midday, directly challenging the 0% probability assumption [3].

A power-user evaluating this market programmatically would monitor real-time Wunderground feeds for London City Airport, cross-referencing with NWP model updates that can reprice contracts within minutes [8]. The primary catalyst is the incoming heatwave forecast, which predicts sustained high UV levels, warm nights with limited cooling, and only a slight risk of isolated thunderstorms that might briefly disrupt the peak [3]. Traders should watch the Met Office’s hourly updates for London City Airport, where current conditions show falling pressure and high humidity—often precursors to rapid temperature shifts [4][6]. The dependency on Wunderground’s official daily record means any data lag or station anomaly could alter resolution, making automated scrapers essential for capturing the exact peak before settlement [1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on July 6? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.