Highest temperature in Hong Kong on June 30?

Platform comparison

Market context

The real-world event at the heart of this market is the peak daytime temperature recorded by the Hong Kong Observatory on 30 June 2026, measured in degrees Celsius to one decimal place. In prediction markets, a YES share means you believe the highest temperature will fall within the specific range the market is betting on (here, implied to be 31°C or 32°C), while a NO share means you expect it to be outside that range. The current crowd-implied probability of 96% YES suggests traders are highly confident the temperature will land in that bracket, with Polymarket data showing 32°C as the leading outcome at 60% and 31°C at 28% [1].

Historically, late June in Hong Kong typically sees maxima between 28°C and 32°C, with the highest monthly mean maximum for June recorded at 32.4°C in 2016 [9]. Recent conditions support this pattern: the Observatory recorded a year-high of 34.6°C on 27 June during the hottest "Mangzhong" solar term, but forecasts indicate a sharp shift to wet weather with temperatures dropping to 26–30°C by Sunday [3]. This aligns with long-term HKO guidance predicting above-normal heat for June–August, yet model consensus shows limited risk of extremes above 32°C absent major atmospheric shifts [2].

Traders should monitor the Hong Kong Observatory’s daily extract for the "Absolute Daily Max" once finalized, as the market cannot resolve until this data is published [4]. Key catalysts include the nine-day rain event starting this weekend, which is expected to bring heavy showers and thunderstorms peaking on Sunday and Monday, cooling temperatures significantly [3]. Additionally, the UV index forecast for 30 June warns of very high intensity (around 10), a factor that often correlates with clear, hot skies before rain arrives [10]. Any revisions to temperatures after initial publication will not affect the market’s resolution [2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on June 30? 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 Prediction Market UK, 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.