Highest temperature in Hong Kong on May 23?

Platform comparison

Active sub-markets

Market context

On 23 May 2026, the Hong Kong Observatory will record the day's highest temperature in Celsius, and this market will settle to whichever range bracket contains that figure. The Observatory's official "Absolute Daily Max" measurement, published in the Daily Extract once data is finalised, serves as the sole resolution source. Settlement occurs at 12:00 UTC on that date, though finalisation of the actual temperature reading may extend beyond the market close.

Hong Kong's May temperatures typically range between 28–32°C, with occasional peaks above 33°C during early heat waves. Historical May records show the Observatory has recorded highs of 35.5°C (May 2003) and 34.8°C (May 2015), though such extremes remain uncommon. The 0% crowd probability across all temperature brackets suggests either incomplete market seeding or genuine uncertainty about which specific range will resolve. Traders comparing this market across platforms—Polymarket's decimal odds format versus Kalshi's binary structure, or Betfair's commission-based model—will find the lack of early price discovery a common friction point; Smarkets' lower-fee structure may attract longer-dated weather traders, whilst Polymarket's liquidity depth typically emerges only after initial crowd participation.

Catalysts for May 2026 include the Hong Kong Meteorological Department's seasonal forecasts (typically issued in April) and any tropical cyclone activity in the Western Pacific, which can suppress temperatures or trigger sudden heat spikes. The Observatory publishes daily forecasts at weather.gov.hk; traders should monitor April 2026 seasonal outlooks and any El Niño or La Niña signals from the Japan Meteorological Agency, which influence regional temperature patterns two to three months ahead.

Methodology

This page compares Highest temperature in Hong Kong on May 23? 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 PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

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 PolyGram?

Zero. PolyGram 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, PolyGram 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.