Highest temperature in London on June 19?

Platform comparison

Active sub-markets

Market context

London’s highest temperature will be set by the reading at London City Airport, so the key real-world event is a single daytime high on 19 June rather than a citywide average. At 0% YES in the 30°C-or-higher framing, the market is effectively saying the current information set does not support an extreme outcome, even though London has already seen 26.6°C at Kew Gardens this year and other forecasts have pointed to a warm spell across the capital and south-east England.[7][3]

The main comparable reference point is the prior day’s closely related market, which was already pricing a very warm result at London City Airport, showing 26°C at 100% and no support for cooler brackets.[2] That matters because temperature markets often reprice quickly when the latest forecast run shifts by just 1–2 degrees, especially when the settlement depends on a specific station and a same-day maximum rather than a broader London forecast. The current crowd view is therefore best read as a snapshot of prevailing heat expectations, not a stable probability for the final station reading.[1][2]

For access and compliance, the practical issue is whether the venue can be used under German and US rules: under Germany’s GlüStV framework, prediction markets with gambling characteristics can face licensing and distribution constraints, while US CFTC reach can matter if a product is treated as a derivatives-style contract offered to US persons. On the platform side, “no-KYC up to $1,500” means a user may be able to trade small sizes without completing full identity verification, but that does not remove country restrictions, platform checks, or geofencing for this specific market.[1]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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?

On Polymarket KYC UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket KYC UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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.

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.