Highest temperature in Hong Kong on July 21?

Platform comparison

Market context

Hong Kong faces a critical heat assessment on 21 July 2026, as the Hong Kong Observatory will record the day’s absolute maximum temperature to settle a prediction market where the crowd currently assigns zero probability to any outcome exceeding the lowest threshold. Current 9-day forecasts indicate sea surface temperatures at North Point reached 25°C this morning, while seasonal projections for July through September suggest temperatures will likely be normal to above-normal due to the prevailing ENSO status [2][3]. This climatic backdrop contradicts the market’s 0% implied probability, as historical July data in Hong Kong frequently sees peaks well above 30°C, making the current pricing appear statistically detached from established meteorological patterns.

Historical records from the Hong Kong Observatory show that July is consistently one of the hottest months, with daily maximums often reaching 33°C to 35°C in recent years, rendering a 0% chance for higher ranges highly anomalous. Comparable cases from previous summers demonstrate that even with normal rainfall chances, heatwaves driven by subtropical ridges routinely push temperatures into the upper ranges, suggesting the market has failed to account for standard seasonal volatility [3]. Traders should view this discrepancy as a potential mispricing rather than a signal of an unusually cool day, given the region’s typical thermal behaviour during mid-summer.

The primary catalyst for resolution remains the publication of the “Daily Extract” containing the finalized “Absolute Daily Max” figure, which the Observatory releases after data verification. No political debates or campaign disclosures influence this weather event, but traders must monitor the Observatory’s official updates for the specific temperature value once the settlement window closes at 12:00 UTC on 21 July [1]. The market leans entirely on this meteorological dependency, with the outcome determined solely by the official recorded figure rather than any external forecast models or crowd sentiment shifts.

Sources: 1 · 2 · 3

Methodology

This page tracks Highest temperature in Hong Kong on July 21? across four political prediction venues. Live odds come from the Polymarket order book (the deepest political prediction-market book). Kalshi is the CFTC-regulated US alternative, Betfair the established UK sports-exchange with politics markets, Manifold the open play-money variant. For users geo-blocked from Polymarket directly, brokers like Election Predictions UK provide a 0%-fee route into the same order book.

Resolution & payout

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

FAQ

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Are political prediction markets legal in my country?

It varies. They sit in legal gray areas in most jurisdictions. Polymarket is geo-blocked from US/UK/EU; some broker frontends have a different geo footprint. Trade only with capital you can afford to lose, and only if you understand the legal status in your jurisdiction.

Which political events have the biggest volume?

US Presidential election, party nominations (DNC/RNC), Senate majorities, individual state outcomes (Pennsylvania, Michigan, Wisconsin), and major European elections. Peak markets reach $50-500M per event.