Highest temperature in Hong Kong on June 29?

Platform comparison

Market context

The real-world event is the daily maximum temperature recorded by the Hong Kong Observatory on 29 June 2026, specifically the highest degree Celsius reached that day. This single data point will determine which temperature range the prediction market resolves to, with the official figure published only after the relevant Daily Extract is finalized.

Historical June data frames the current 0% YES probability as a mispricing, given that Hong Kong routinely experiences highs between 34°C and 37°C in late June. The Observatory’s seasonal forecast for June–August 2026 explicitly predicts above-normal temperatures, while recent records show the city hitting 34.6°C in May 2026 and New Territories reaching 37°C during extreme heat warnings earlier this year[2][3][5]. Programmatically, a power-user would script a bot to monitor the HKO climate API for the Daily Extract update, comparing the absolute daily max against the market’s range thresholds to execute conditional orders before settlement.

Traders must watch the HKO’s official Daily Extract publication schedule, as the market cannot resolve until this data is finalized. The catalyst is the release of the “Absolute Daily Max (deg. C)” for 29 June, which depends on the completion of the observational cycle and data validation. Recent news confirms the Observatory has warned of extreme heat events in 2026, with temperatures expected to be abnormally high across the year[4]. A conditional order strategy would trigger only once the Daily Extract confirms the temperature, ensuring no premature exposure to the 0% implied probability before the official figure is verified.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket App UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket App UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.