Highest temperature in Hong Kong on August 3?

Platform comparison

Market context

Hong Kong’s afternoon high on 3 August is the event, and the market is pricing a **0% YES** chance that the day’s maximum will land in the target band. On that read, the crowd is treating the favourite as a non-event and the underdog as a very narrow, low-odds outcome: the only value case is a sharp upside surprise against the prevailing forecast, while the consensus sits firmly with a middling, ordinary summer reading rather than an extreme spike.

Historically, August in Hong Kong is a hot, humid month, with typical daytime highs around **31°C** and a recurring rain/typhoon risk, which usually caps enthusiasm for very high-temperature outcomes even when the city feels oppressive.[2][12][18] The current published outlooks are not pointing to a heat-breakout day: one forecast for 3 August shows a high near **31°C**, while another hourly forecast is much cooler, around the mid-20s Celsius with rain and cloud.[2][3] That split matters for handicapper framing: the market’s 0% implies the consensus is effectively “normal August warmth, not an outlier”, and any value on the contrarian side depends on whether the final Observatory observation runs hotter than the softer guidance suggests.[1][2][3]

The main catalysts to watch are the Hong Kong Observatory’s own daily extract and the timing of final publication, because this market cannot resolve until the **Absolute Daily Max (deg. C)** for 3 August appears in the official record.[10][9] In practical terms, traders should focus on the Observatory’s regional readings and whether local convective showers, cloud cover, or a tropical disturbance suppress the peak temperature below forecast ranges.[13][15] If the day develops more like the warmer end of the published guidance, the underdog case improves; if rain bands hold and the midday maximum stays in the mid-to-high 20s, the 0% consensus looks much more justified.[2][3][13]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on August 3? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 Who Will Win 2026. 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.

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.