Highest temperature in Hong Kong on August 3?

Platform comparison

Market context

The event is whether the Hong Kong Observatory’s **highest temperature** on 3 August 2026 lands in the market’s quoted Celsius band, with the contract settling off the Observatory’s final “Absolute Daily Max” once the daily extract is published. The crowd is currently pricing a **0% YES** headline probability on this specific contract, which is starkly at odds with the contract page on Polymarket, where the leading outcomes sit around **27°C at 38%** and **28°C at 30%**, with **32°C or higher below 1%**.[2][5]

Historically, Hong Kong’s August maxima usually cluster in the high-20s to low-30s, so the market’s centre of gravity is around ordinary summer heat rather than extreme readings.[1][6][8] That said, recent local reporting shows how quickly Hong Kong can spike: the Observatory has already logged 2026 highs above **34°C** on separate days, including a reported **34.3°C** and other “hottest day of the year” marks, which keeps the upper tail alive even if it is not the base case.[11][13][14] The key divergence here is not between sportsbook lines and the exchange-style market so much as between the contract’s near-zero crowd read and the more conventional analyst-style expectation for a mid- to upper-20s result.

Traders should watch the Hong Kong Observatory’s daily readings, any afternoon temperature peak before the cut-off, and the timing of the final extract, because the market resolves only after the published daily data is finalised.[5] Weather commentary for early August points to showers and cloud cover suppressing maxima, which supports the market’s bias towards **27–28°C** and helps explain why the platform’s live probabilities are concentrated there rather than in the low-30s.[2][12] The main dependency is simple: if cloud and rain linger through the afternoon, the contract favours the middle bands; if sunshine breaks through, the upside bands can reprice quickly.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on August 3? 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 Kalshi vs Polymarket, 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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket 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.