Highest temperature in London on July 17?

Platform comparison

Market context

The market hinges on the highest temperature recorded at London City Airport (EGLC) on 17 July 2026, with settlement tied to Wunderground’s daily history for that station. Today, current readings show 13°C at EGLC with high humidity and falling pressure, while nearby airport data suggests 18°C, indicating a cool, unsettled start to the day [1][2]. With the crowd-implied probability at 0% YES, the market currently assumes the temperature will fall outside the defined winning range, likely due to these immediate conditions.

Historically, July in London averages around 23°C, but Met Office records confirm heatwaves frequently push temperatures above 30°C, making extreme highs a recurring seasonal feature rather than an anomaly [3]. A 0% probability is therefore statistically fragile; programmatically, traders should model this as a binary event where a single heatwave spike invalidates the current pricing. Conditional order bots would typically wait for a sustained rise above 25°C before entering, as isolated spikes often fail to trigger resolution if the daily maximum remains below the threshold.

Key catalysts include the Met Office’s 24-hour forecast updates and any sudden shifts in southerly wind flow, which can rapidly elevate temperatures. Traders monitoring this market programmatically should track real-time Wunderground feeds for EGLC, as the resolution source is explicitly tied to this station’s daily maximum. A recent shift in pressure patterns, noted as falling at 1012mb, suggests potential for rapid change, meaning automated systems must be configured to react to minute-level temperature jumps rather than relying on daily averages [1].

Sources: 1 · 2 · 3

Methodology

This page reviews Highest temperature in London on July 17? 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 Bot UK, 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

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.

Do I need to KYC for this market?

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