Highest temperature in Hong Kong on August 9?

Platform comparison

Market context

Polymarket is currently pricing the Hong Kong daily high on this contract at a low level in USDC on Polygon, with conditional tokens tied to the eventual Hong Kong Observatory reading for 9 August 2026. The market’s crowd-implied probability is sitting at 0% for a YES-style outcome in the way you have framed it, so the practical read is that traders are assigning very little weight to the higher temperature bands at present, despite the contract only settling once the Observatory publishes the final “Absolute Daily Max (deg. C)” in its Daily Extract.

For context, Hong Kong’s early-August climatology is hot rather than extreme: the 1991–2020 normal for 9 August lists a mean daily maximum of 31.6°C and a mean temperature of 29.0°C, which is a useful anchor when judging whether the day is likely to land in the low, mid or upper 30s.[4] In August 2025, the Observatory recorded a mean daily maximum of 31.7°C for the month, showing that sustained heat is routine even when rainfall is heavy.[2] On comparable hot-season days, the market tends to concentrate around the outcomes just above the climatological normal rather than on exceptional spikes, because the final settlement uses the single highest Hong Kong Observatory reading, not a citywide average.[12]

The immediate trader watchpoints are the Observatory’s short-range forecasts, its hourly readings, and any tropical-cyclone or monsoon-related updates that alter cloud cover, wind and subsidence, all of which can change the ceiling temperature quickly.[1][6][15] Recent reporting from the Observatory has already pointed to hot daytime conditions around 9 August, with local media carrying its warning of a very hot day and a 34°C peak in one briefing, so any fresh bulletin on the day itself matters more than the broader seasonal average.[13] The key dependency is the final publication of the Daily Extract; until that appears, even a settled-looking intraday high remains provisional for resolution purposes.[15]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on August 9? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Scam?, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

UK Frequently Asked Questions

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 Scam?. 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.