Highest temperature in Hong Kong on July 31?

Platform comparison

Market context

The key real-world event is the Hong Kong Observatory’s final **daily maximum temperature** reading for 31 July, which will determine the temperature band that settles this market. Hong Kong is in its hottest stretch of the year, and late-July readings often sit in the low-30s Celsius; AccuWeather’s forecast for 31 July showed a high around 31°C to 32°C, which is consistent with the city’s recent summer pattern.[2][13]

For historical framing, the Observatory’s July record list shows how wide the upside can be: the highest monthly maximum temperature for July is 35.7°C, with other top July extremes at 35.6°C and 35.4°C.[3] Recent comparables point in the same direction. In July 2023, the Observatory reached 36.1°C on 27 July, one of the hottest July readings on record, while on 31 July that year showers returned and the day did not finish near the month’s peak.[8] That matters for this market because the settlement depends on the single highest reading on the date, not the month’s average.

The main catalyst to watch is the Observatory’s same-day bulletins and the final “Daily Extract” publication, since this market cannot resolve until that data is posted.[7] Intraday hourly readings are the immediate signal: at 2 p.m. on 31 July, the Observatory was already at 31°C, with nearby stations such as Cheung Chau at 33°C and Kowloon City, Happy Valley and Wong Tai Sin at 32°C, indicating there was still room for the day to climb.[7] Traders should lean on the Observatory’s updates rather than the crowd-implied 0% YES price, which effectively assumes an outcome in the lowest bucket despite the live heat profile and the city’s established July climatology.[2][3]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in Hong Kong on July 31? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

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.

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 Trump Prediction 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.