Highest temperature in London on June 16?

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Active sub-markets

Market context

On 16 June 2026, the highest temperature recorded at London City Airport will settle this market into one of several defined ranges. The settlement source is Wunderground's historical weather data for that specific station, measured in Celsius. Traders selecting YES are betting the temperature will fall within their chosen bracket; the 0% crowd probability suggests either extreme confidence in a particular range or sparse liquidity across all options.

London's June climate typically produces highs between 20–24°C, though heat waves can push readings into the upper twenties. The 2022 June heatwave saw temperatures exceed 30°C across southern England, demonstrating that outlier scenarios do occur. Historical June data from City Airport shows variability tied to Atlantic weather patterns and urban heat effects; comparing this market's implied probabilities across platforms reveals how different books price tail-risk scenarios. Kalshi's decimal-odds format and Betfair's fractional odds express the same underlying probability differently, yet both should theoretically converge on fair value. Fee structures—Kalshi's fixed spread versus Betfair's commission model—affect the effective odds traders receive, particularly on lower-probability ranges where bid-ask spreads widen.

The Met Office's seasonal forecasts and medium-range models become actionable signals from mid-May onwards. Traders should monitor early-June weather patterns and any Atlantic blocking systems that could drive warm continental air into the UK. Polymarket's cross-border accessibility and Smarkets' UK-focused regulatory approach create different trader pools, potentially fragmenting liquidity on this niche weather contract. Settlement timing at 12:00 UTC on 16 June locks in the daily high; any platform disputes over Wunderground's data feed would require escalation to their resolution team.

Methodology

We read Highest temperature in London on June 16? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

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). Kalshi Alternative UK 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 Kalshi Alternative 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?

Kalshi Alternative 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.

What does it cost to trade on Kalshi Alternative UK?

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

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Kalshi Alternative UK triggers a quick verification flow that finishes in 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.