Highest temperature in Hong Kong on July 8?

Platform comparison

Market context

The Hong Kong Observatory forecasts a daily maximum between 30°C and 32°C for 8 July 2026, with cloud cover and potential light rain patches likely suppressing temperatures below the 31°C threshold that would trigger a YES outcome. This real-world constraint explains why the contract currently prices at 0% YES on Polymarket, reflecting the market’s confidence that the absolute daily max will not breach the upper bound of the target range.

Historical July data frames this probability: early-month highs average 30.4°C, while the seasonal forecast for July–September 2026 predicts normal to above-normal temperatures, yet the immediate outlook for 8 July remains mainly cloudy with temperatures capped at 20°C in the early morning and rising only gradually [1][3]. The 0% pricing aligns with comparable cases where cloud cover and rain patches in early July have consistently kept highs below 31°C, even during years with above-normal seasonal trends [3][5].

Traders should monitor the Observatory’s final “Daily Extract” release, which will publish the verified “Absolute Daily Max (deg. C)” once data is finalized, as this is the sole resolution source [5]. Key catalysts include any sudden shifts in cloud cover or rain intensity announced in the regional forecast for 8–9 July, which could alter the maximum temperature, and the timing of the USDC settlement on Polygon once the conditional token resolves [6][7]. The forecast’s mention of light rain patches and mainly cloudy conditions remains the primary dependency for the 0% probability holding [6].

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Kalshi 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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.