Highest temperature in Hong Kong on July 18?

Platform comparison

Market context

On 18 July 2026, the Hong Kong Observatory will record the day's highest temperature in degrees Celsius. This market settles on that single data point once the Observatory publishes its daily extract, which typically occurs within 24–48 hours of the observation period closing at noon UTC.

Hong Kong's July temperatures are remarkably consistent year-on-year, with historical daily maxima clustering between 31–34°C during mid-summer. The 30-year average high for mid-July sits near 32.5°C, though extremes have ranged from 29.8°C to 36.3°C. The 0% crowd-implied probability across prediction markets suggests traders are either awaiting range-selection mechanics to clarify or treating this as a placeholder until the specific temperature bands are published. Comparable weather-settlement markets on Kalshi and Polymarket typically see meaningful probability distribution only once discrete outcome brackets are defined; absent that granularity, traders often abstain. Recent Hong Kong summer conditions (June–early July 2025) showed typical monsoon patterns with afternoon highs in the 32–33°C range, providing a baseline for assessing outlier scenarios.

The settlement hinges entirely on Hong Kong Observatory data publication timing. Traders should monitor the Observatory's daily extract release schedule, which occasionally experiences delays during typhoon season or system maintenance. No scheduled weather events or forecasting announcements typically move this market before the settlement window closes; the outcome is determined by actual meteorological conditions on the day itself, making this contract purely a temperature-prediction instrument rather than an event-driven trade.

Methodology

This page reviews Highest temperature in Hong Kong on July 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 PolyGram, 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

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram 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.