Highest temperature in Hong Kong on May 31?

Platform comparison

Active sub-markets

Market context

Hong Kong's daily maximum temperature on 31 May 2026 will be recorded by the Observatory and published in its Daily Extract climate data. The settlement window closes at noon UTC on that date, though the official temperature reading typically becomes available within hours of the observation period ending at 9 p.m. local time. The Hong Kong Observatory's historical records form the sole resolution source, measured to one decimal place in Celsius.

May temperatures in Hong Kong cluster between 28–32°C, with extremes occasionally reaching 33–34°C during early-season heat waves. The 0% crowd probability reflects genuine uncertainty rather than consensus that cooler readings are certain; sparse liquidity in weather markets often produces extreme implied odds before meaningful deposit flows arrive. Historical May 31st maxima across recent decades show variability of roughly 4–5°C, making any single temperature band plausible without dominant favourites emerging.

Traders monitoring this market should track the Hong Kong Meteorological Society's seasonal outlooks and any tropical cyclone activity in the South China Sea during late May, as both influence atmospheric conditions. Deposit friction remains material for weather-specific markets: SEPA transfers and USDC on-ramps reduce settlement delays compared to traditional fiat withdrawal rails, allowing faster position entry as May approaches. Book depth typically builds two to three weeks before settlement as traders with regional exposure hedge exposure or arbitrage against local betting markets.

Methodology

We track Highest temperature in Hong Kong on May 31? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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 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.

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 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.

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.