Highest temperature in Hong Kong on August 19?

Platform comparison

Market context

Hong Kong's meteorological authority will record the single highest temperature reached on 19 August 2026, measured to one decimal place in Celsius. This reading becomes the settlement value once the Hong Kong Observatory publishes its Daily Extract for that date, typically within days of the observation period closing. The 0% crowd probability reflects the market's current state rather than any forecast consensus; temperature ranges will populate as the date approaches and historical analogues become clearer.

August represents Hong Kong's peak summer season, with daily maxima typically ranging between 31–34°C depending on monsoon patterns and urban heat effects. Historical data from the Observatory shows considerable year-to-year variation: some August days have peaked near 36°C during heat waves, whilst others remain closer to 30°C under cloud cover or offshore flow. Reviewing the Observatory's climate archive for previous 19 August readings provides the most direct calibration—traders automating range selection should query the historical "Absolute Daily Max" dataset to establish the distribution of outcomes for this specific calendar date across available decades.

Tropical cyclone activity and upper-level pressure systems drive the primary catalysts for extreme heat or moderation in mid-August. The Hong Kong Observatory issues seasonal forecasts and ten-day outlooks that traders can monitor programmatically; these typically become more precise 7–10 days before the target date. Settlement hinges entirely on official Observatory publication, so traders building conditional orders should account for a 2–3 day lag between the observation date and data availability on the Observatory's climate portal.

Methodology

This page reviews Highest temperature in Hong Kong on August 19? 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 Kalshi Fees, which mirrors the Polymarket order book at 0% fees.

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 Kalshi Fees. 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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.