Highest temperature in Hong Kong on May 31?

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Market context

On 31 May 2026, the Hong Kong Observatory will record a daily maximum temperature in Celsius. Polymarket currently prices all temperature ranges at 0% YES, reflecting the market's inability to settle until official data publishes after that date. The contract will resolve to whichever bracket contains the single highest reading logged by the Observatory's instruments, measured to one decimal place and extracted from their Daily Extract records.

Hong Kong's May climate sits at the threshold between spring and early summer, with historical daily maxima typically ranging from 28°C to 32°C. The Observatory's records from recent May 31st observations show considerable year-to-year variation: 2023 recorded 31.2°C, 2022 saw 29.8°C, and 2021 peaked at 30.5°C. This volatility reflects the influence of pre-monsoon weather patterns and occasional tropical systems that can suppress or elevate temperatures significantly within a single day. Traders should note that late May marks the tail end of spring before the southwest monsoon intensifies, making both moderate and elevated readings plausible.

Settlement depends entirely on the Hong Kong Observatory publishing finalised daily data through their Climate Information Services portal. The Observatory typically releases Daily Extract records within days of observation, though official confirmation can take longer during periods of data verification. Traders should monitor the Observatory's website directly rather than relying on secondary sources, as the resolution hinges on their specific "Absolute Daily Max" figure. No weather forecasts or predictions made before May 31st will alter the contract's outcome—only the actual recorded maximum temperature matters.

Methodology

This page is a comparison snapshot: one live quote (Polymarket), four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Scam?, which mirrors the Polymarket order book directly.

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 Scam?, 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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket Scam? triggers a quick verification flow that finishes in minutes.