Highest temperature in Hong Kong on July 12?

Platform comparison

Market context

On 12 July 2026, the Hong Kong Observatory will record the day’s highest air temperature in degrees Celsius, a single figure that determines how this prediction market settles. In prediction markets, a YES share pays out if the event occurs as defined, while a NO share pays out if it does not; traders buy and sell these shares to express their view on the outcome, with prices shifting as new information arrives. Here, the market asks which temperature range contains the peak reading, and the current crowd-implied probability of 0% YES suggests traders believe the specific outcome in question is virtually impossible.

Historical July data frames how to interpret this near-zero probability. July is typically Hong Kong’s hottest month, with the highest monthly mean maximum temperature reaching 32.9°C in 2007 and recent years showing consistent warmth, including 2025, the city’s sixth warmest year since 1884, when all 12 months were warmer than usual [4][5]. Just yesterday, on 11 July 2026, the market priced 34°C at 100% certainty, and on 12 July, 34°C remains the frontrunner at 50%, with 33°C at 46%, indicating traders expect temperatures near or above 34°C rather than lower ranges [1][2]. This context makes a 0% probability for a lower range plausible if the event in question is, for example, “27°C or below”.

Traders should monitor short-range weather guidance from the Hong Kong Observatory, which updates daily and includes the “Absolute Daily Max” once finalized in the Daily Extract [1][7]. The immediate catalyst is the publication of the official figure for 12 July, which will resolve the market once data is confirmed. Recent news highlights Hong Kong’s record-breaking heat, with temperatures hitting 34.6°C earlier this week and a hail warning issued amid the swelter, underscoring the intensity of the current heatwave [3]. The settlement window ends at 12:00 UTC on 12 July 2026, after which the Observatory’s finalized data will determine the outcome.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 Prediction Market UK. 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'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.