Highest temperature in Hong Kong on August 17?

Platform comparison

Market context

On 17 August 2026, the Hong Kong Observatory will record the day's maximum temperature in degrees Celsius, rounded to one decimal place. That single reading will determine which temperature band resolves YES on Polymarket. Currently, the market shows 0% implied probability across all outcome ranges, a pricing anomaly that typically signals either illiquidity or settlement uncertainty rather than genuine confidence in any specific outcome.

Hong Kong's August temperatures are remarkably consistent year-on-year. Historical data from the Observatory shows daily maxima in mid-August cluster tightly between 31°C and 34°C, with extreme outliers rare. The 30-year average for 17 August sits near 32.5°C. Heatwaves pushing above 35°C occur roughly once per decade in August; conversely, readings below 30°C are virtually absent. This tight historical distribution means most outcome bands carry meaningful probability weight, yet the market's current 0% reading suggests traders are either waiting for resolution mechanics clarification or avoiding the contract entirely due to low liquidity on Polygon.

The Hong Kong Observatory publishes daily climate data with a lag of several days, typically appearing in their "Daily Extract" records within a week of the date. Traders should monitor the Observatory's website directly rather than relying on secondary sources, as the resolution source explicitly requires the "Absolute Daily Max" figure from their official climate database. Tropical cyclone activity in early-to-mid August could shift temperatures materially; the 2023 and 2024 typhoon seasons both affected Hong Kong's August weather patterns significantly. Settlement cannot occur until the Observatory publishes verified data for 17 August 2026.

Methodology

This page reviews Highest temperature in Hong Kong on August 17? 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 Alternative UK, 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 Alternative UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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%.