Lowest temperature in Hong Kong on August 9?

Platform comparison

Market context

Hong Kong’s daily minimum on 9 August will be set by the Hong Kong Observatory’s final “Absolute Daily Min (deg. C)” for that date, so the market is really a bet on whether the city avoids or sustains an overnight cool-down before the official extract is published. August in Hong Kong is usually very warm and humid: the Observatory’s 1991–2020 normals put the 9 August mean minimum at 26.9°C, with a mean daily temperature of 29.0°C, which makes anything materially below the high-20s unusual but not impossible.[2]

That is the historical lens traders should use for the current 0% YES pricing. Recent comparable summers show how sticky the nights can be even after very hot afternoons: the Observatory’s August 2024 summary described a persistently very hot spell from 3–9 August, while August climatology still points to warm minima rather than sharp drops.[7][2] In other words, the market is leaning on the idea that the lowest temperature will remain in a familiar August band rather than turning notably cool, and the crowd has effectively priced the event as an extreme outlier.

The main catalyst is the weather itself, not a political calendar-style trigger: updates from the Hong Kong Observatory’s forecast pages, any late-day thunderstorm or rain band, and the overnight minimum before the final daily extract are what matter most.[6][12] Short-term history suggests the key dependency is whether rain or cloud cover holds temperatures up through the night; the last 15 days have already included very warm readings, with Hong Kong reaching 95°F on 8 August in one history feed, reinforcing the idea that the setup entering settlement is hot.[5][1] The market cannot resolve until the Observatory publishes the final data for 9 August, so the final read will come from the official extract rather than live forecasts.[3]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page tracks Lowest temperature in Hong Kong on August 9? 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.

UK Frequently Asked Questions

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

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.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Election Predictions UK route into the same order book at 0% fees.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.