Highest temperature in Hong Kong on August 18?

Platform comparison

Market context

The Hong Kong Observatory will record the highest temperature in Hong Kong on 18 August 2026, measured to one decimal place in degrees Celsius. This single daily maximum will determine which temperature band resolves as correct, with settlement finalised once the Observatory publishes its "Daily Extract" data for that date.

August is Hong Kong's hottest month climatologically, with daily maxima typically ranging between 31 and 33 degrees Celsius. Historical records show considerable year-to-year variation; the absolute maximum temperature ever recorded in Hong Kong is 39.9°C (September 1967), whilst August records have peaked at 37.8°C (August 1980). The 0% crowd probability suggests traders are either uncertain about available temperature bands or treating this as a placeholder market pending full contract specifications. Comparable weather markets on Polymarket and Kalshi show measurable divergence when settlement depends on official meteorological data; traders often discount markets until historical precedent clarifies typical ranges for the specific location and season.

The Hong Kong Observatory's forecasting accuracy for mid-range temperatures (30–35°C) typically exceeds 85% for five-day outlooks, though August conditions remain sensitive to tropical cyclone activity and monsoon patterns. Traders should monitor tropical cyclone warnings issued by the Regional Specialized Meteorological Centre (RSMC) in New Delhi and any significant heat-dome formation across Southeast Asia in early August 2026. The settlement window closes at 12:00 UTC on 18 August, requiring the Observatory's official daily extract to be published before final resolution; delays in data publication have historically extended settlement timelines for weather contracts by 48–72 hours.

Methodology

We track Highest temperature in Hong Kong on August 18? 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

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.

FAQ

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.

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.