Highest temperature in London on July 16?

Platform comparison

Market context

London City Airport is recording 13°C today, a cool start that aligns with the market’s current 0% probability for any extreme heat outcome. On Polymarket, traders are using USDC on the Polygon network to buy conditional tokens for specific temperature bands, with the crowd overwhelmingly pricing in the 74–75°F (23.3–23.9°C) range as the eventual settlement. This pricing reflects a consensus that July 16, 2026, will not see record-breaking highs, despite London’s occasional summer spikes.

Historically, mid-July temperatures in London rarely exceed 25°C at EGLC, with the last notable heatwave occurring in 2022 when temperatures briefly hit 38°C across the city but not consistently at the airport station. Comparable years like 2023 and 2024 saw maximums around 22–24°C, reinforcing the market’s cautious stance. The 0% YES probability suggests traders view a significant heat event as statistically improbable based on these patterns.

Traders should monitor the Met Office’s daily forecast updates and any sudden shifts in the southerly wind flow, which can bring warmer air from continental Europe. A recent BBC Weather report notes falling pressure and high humidity, conditions that typically suppress extreme daytime highs [2]. With settlement locked to Wunderground’s EGLC data at 12:00 UTC on July 16, 2026, any deviation from the 23–24°C range would require an unexpected atmospheric shift.

Sources: 1 · 2

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

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

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 PolyGram 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.