Highest temperature in Hong Kong on July 9?

Platform comparison

Market context

The underlying event is the highest temperature recorded by the Hong Kong Observatory on 9 July 2026, measured in degrees Celsius to one decimal place. This single data point, once finalized in the Daily Extract, will determine the market resolution. The current crowd-implied probability of 0% for a specific outcome suggests the market is pricing in a temperature range that is either highly unlikely or currently misaligned with the prevailing forecast, which anticipates normal to above-normal temperatures for the July–September period [3].

Historically, Hong Kong’s July highs typically range between 32°C and 35°C, with the average high for the month sitting near 32°C (89°F) [1][8]. While 2026 forecasts indicate daily highs could reach 35°C (95°F), the 0% probability implies the market may be betting on a lower threshold that contradicts seasonal norms. A power-user approaching this programmatically would script a bot to monitor the HKO’s Daily Extract feed, comparing real-time readings against the 32°C threshold to trigger conditional orders once the data is published [5].

Traders must watch the HKO’s official release schedule for the 9 July Daily Extract, as the market cannot resolve until this data is finalized. Recent seasonal forecasts confirm normal to above-normal temperatures, with ENSO conditions supporting warmer weather [3]. Any sudden shift in cloud cover or rainfall, which is also forecast to be normal to above-normal, could suppress peak temperatures below the expected range. The key dependency is the timely publication of the “Absolute Daily Max” figure, which remains the sole resolution source [5].

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

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.

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 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.

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.