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 in degrees Celsius to one decimal place. This market resolves based on the absolute daily maximum temperature published in the Observatory's Daily Extract once data is finalised.

August is Hong Kong's peak summer month, with historical daily maxima typically ranging between 32°C and 35°C. The 0% crowd probability suggests traders expect the settlement range to fall outside whatever upper threshold this market has defined, though the exact range boundaries are not specified in available documentation. Hong Kong's August temperatures have shown consistency over decades; the Observatory's climate records indicate that extreme heat days above 36°C occur infrequently during this period, though they do happen. The 2023 summer saw several days exceeding 35°C, and 2022 recorded temperatures near 36°C in mid-August. This historical pattern means consensus may be underweighting the tail risk of an unusually hot day, particularly if a heat dome or tropical system affects the region.

The settlement window closes on 18 August 2026 at 12:00 UTC, but the market cannot resolve until the Hong Kong Observatory publishes its Daily Extract data for that date, typically released within days of the observation period. Traders should monitor the Observatory's seasonal forecasts and any tropical cyclone activity in the weeks preceding mid-August, as these factors directly influence maximum temperatures. El Niño or La Niña conditions in the preceding months may also shift baseline temperatures upward or downward.

Methodology

This page reviews Highest temperature in Hong Kong on August 18? 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 Who Will Win 2026, 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.

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.