Highest temperature in Hong Kong on June 21?

Platform comparison

Active sub-markets

Market context

Hong Kong’s highest temperature today will be set by the Hong Kong Observatory’s daily maximum, measured in Celsius to one decimal place, so the market is really a bet on whether the city can avoid a late-day spike above the current summer baseline. June in Hong Kong is already a high-heat month: the Observatory’s June rankings show the monthly mean maximum has reached 32.4°C on record, with 32.3°C and 31.7°C in other hot June years.[2]

Recent comparisons matter more than the crowd’s 0% yes price suggests. Hong Kong has already seen extreme June heat in prior years, including a reported 36.1°C peak on an earlier scorching day and a matched record for the hottest summer solstice at 34°C, which shows that very high readings are plausible even before the deepest part of summer arrives.[1][4] Climate data from the Observatory also indicates a long-run warming trend, with annual mean temperature rising by 0.35°C per decade during 1996-2025, a background that supports fatter tails in the distribution of warm-day outcomes.[9]

For traders, the key catalysts are the Observatory’s intraday updates and the final Daily Extract, because the market cannot resolve until that publication is posted.[7] On a payments-first venue, depth is likely to follow funding convenience: low-friction deposits via SEPA, card-on-ramp options such as Klarna, and quick USDC transfers tend to support faster recycling of capital into short-dated weather books, while withdrawal speed affects how much liquidity stays parked for event risk. With resolution depending on a single city reading and no need for a long information chain, the main edge comes from how quickly fresh funds can enter once temperature forecasts shift.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on June 21? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Polymarket Deposit UK — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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?

On Polymarket Deposit 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 Deposit 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.

What does it cost to trade on Polymarket Deposit UK?

Zero. Polymarket Deposit 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, Polymarket Deposit UK triggers a quick verification flow that finishes in minutes.