Highest temperature in London on June 16?

Platform comparison

Active sub-markets

Market context

On 16 June 2026, the highest temperature recorded at London City Airport will settle into one of several defined ranges. The settlement source is Wunderground's historical weather data for that specific station, measured in Celsius. The current 0% YES probability across major platforms suggests traders are either absent from this market or treating it as a placeholder pending liquidity. Polymarket, Kalshi, Betfair, and Smarkets all carry weather contracts, but they diverge sharply on how they price temperature bands: Polymarket typically uses binary YES/NO structures with decimal odds, whilst Kalshi offers tighter spreads on US-focused weather but limited international coverage, and Betfair's exchange model allows back-and-lay pricing that can reveal sharper disagreement between traders on edge cases.

London's June temperatures have historically ranged between 18°C and 28°C, with the airport station—situated on the Thames estuary—recording slightly cooler maxima than central London due to maritime influence. The Met Office's 30-year average for mid-June is approximately 21°C. A heatwave or anomalous warm spell would push readings toward the upper ranges; conversely, Atlantic low-pressure systems can suppress temperatures into the low 20s or below. No scheduled weather announcements or climate forecasts will be released on the day itself; traders must rely on seasonal patterns and medium-range forecast updates from the Met Office or ECMWF issued in the days prior.

The absence of current trading activity on this market likely reflects its low salience relative to major economic or political events. Kalshi's KYC requirements and US-centric regulatory focus mean it rarely lists international weather contracts with granular precision. Betfair's exchange model would theoretically allow sophisticated traders to exploit forecast revisions, but only if liquidity materialises. Settlement timing at 12:00 UTC on 16 June means the highest temperature will be determined by early afternoon readings, before any evening cooling.

Methodology

This page compares Highest temperature in London on June 16? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). Polymarket Alternative routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Alternative, 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.

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.

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 it cost to trade on Polymarket Alternative?

Zero. Polymarket Alternative routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.