Highest temperature in London on July 13?

Platform comparison

Market context

London City Airport is forecast to hit 27°C today, yet the Polymarket contract for the highest temperature on 13 July 2026 prices the YES outcome at just 2%, implying traders expect a significantly cooler day or a resolution mismatch. This low probability contrasts sharply with the current on-chain frontrunner, where the 27°C outcome commands 52% of the volume, while 26°C sits at 25%, suggesting the market is betting on a specific range rather than a binary extreme [2]. The settlement relies on Wunderground’s daily record for EGLC, meaning any discrepancy between the live forecast and the official historical log could invalidate the 2% view entirely.

Historically, London’s July highs at EGLC average around 22°C, but recent heatwaves have pushed readings well above 35°C, with the UK recording 40.2°C at nearby sites in July 2022 [5]. The Met Office notes that temperatures exceeding 35°C have now occurred in May, June, and July within the same year for the first time, indicating a shifting baseline that makes low-probability heat events more plausible than older climate models suggest [4]. If the 2% price reflects a belief that 2026 will be an anomaly, it ignores the trend of increasingly volatile summer peaks that have become standard in recent years.

Traders should monitor the Met Office’s 12:00 UTC update and Wunderground’s data ingestion schedule, as the market cannot resolve until the first data point for 13 July is published [2]. The BBC Weather forecast for today lists a high of 27°C with sunny conditions, which aligns with the 27°C conditional token dominance but contradicts the 2% YES pricing if the market implies a lower threshold [6]. Any delay in the official Wunderground record or a sudden shift in the forecast due to cloud cover could trigger rapid liquidity shifts on the Polygon network, where USDC shares trade in real-time based on these dependencies [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on July 13? 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

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'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.

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.