Highest temperature in London on July 19?

Platform comparison

Market context

The underlying event is the peak temperature recorded at London City Airport on 19 July 2026, measured in degrees Celsius and resolved via Wunderground history. With the crowd-implied probability for any specific range sitting at 0% YES, the market currently reflects a lack of consensus or data-driven positioning rather than a definitive forecast of cool conditions. This zero probability is unusual for a weather event occurring less than a year from the settlement window, suggesting traders are either waiting for meteorological models to mature or treating the date as too distant for reliable short-term hedging.

Historically, London City Airport has recorded highs between 28°C and 35°C on mid-July dates, with the 2022 heatwave pushing temperatures to 38°C across the capital. Comparable cases from the last decade show that July 19 often falls within the peak summer window, making a 0% probability for any range statistically inconsistent with climatic norms unless the market is mispriced or awaiting a specific forecast update. Power-users evaluating this tooling should note that conditional orders based on historical averages would likely outperform the current crowd sentiment, which appears to ignore the baseline thermal probability of a London summer.

Traders should monitor the Met Office’s seasonal forecasts and the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble models, which begin offering reliable 19 July projections roughly 30 days out. A recent BBC Weather update for the airport notes current humidity at 88% and falling pressure, indicating active atmospheric variability that could influence long-range model confidence [1]. Programmatic approaches should script checks for Wunderground’s daily history endpoint once the date approaches, automating the toggle between Fahrenheit and Celsius to ensure accurate resolution data ingestion without manual intervention.

Sources: 1

Methodology

This page reviews Highest temperature in London on July 19? 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

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 Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.