Highest temperature in London on July 3?

Platform comparison

Market context

The real-world event driving this market is the peak temperature recorded at London City Airport on 3 July 2026, measured in degrees Celsius and resolved via Wunderground data. With the current crowd-implied probability for a specific outcome sitting at 0%, traders must evaluate whether historical patterns support such a dismissal or if the market is mispricing a plausible scenario.

Historical data from early July 2026 shows London City Airport hitting 26.4°C on 2 July, with forecasts for 3 July suggesting a high of 26°C, while the average July maximum across the region is 21.8°C[1][7][9]. The 26°C outcome currently trades at 46% on alternative platforms, indicating that the 0% probability on this specific market may reflect a resolution threshold mismatch rather than a genuine lack of heat[2]. A power-user would programmatically query Wunderground’s daily history endpoint to cross-validate the settlement range against the live 26°C forecast, flagging the discrepancy as a potential arbitrage opportunity.

Traders should monitor the Met Office daily forecast updates and the National Weather Service’s real-time METAR feed for EGLC, as sudden shifts in southerly wind flow or humidity could push temperatures above the 26°C threshold[1][4]. Recent reports confirm a dew point of 13°C and 88% humidity at the station, conditions that often sustain higher peak temperatures when combined with the forecasted 26°C high[1]. No major weather announcements are scheduled, but the dependency on Wunderground’s automated logging means any data gap or time-zone misalignment could invalidate the resolution, making direct API monitoring essential for conditional order execution.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on July 3? 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 Polymarket Review UK, which mirrors the Polymarket order book at 0% fees.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Review UK 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.