Highest temperature in Hong Kong on August 4?

Platform comparison

Market context

Hong Kong’s highest temperature on 4 August will be set by the Hong Kong Observatory’s final “Absolute Daily Max” reading for the day, which is measured in Celsius to one decimal place and only settles once the Daily Extract is published. The current 0% crowd-implied probability for the broad YES side leaves the contract effectively pricing in no consensus around the eventual range, so the first thing traders are really watching is whether the day behaves like a routine wet-season afternoon or a sharper heat spike.

Recent August baselines suggest that the 29°C–30°C band is the natural centre of gravity, with one market snapshot pointing to 30°C as the leading outcome and 29°C close behind. Comparable recent heat in Hong Kong shows the city can move quickly into the mid-30s on strong sunshine days, but that has typically required clear skies and stronger local heating than an unsettled summer setup. Hong Kong also records a lot of day-to-day variation between the Observatory and inland districts, so the central station reading can undershoot the hottest suburb by a wide margin even when the wider territory feels oppressive. [2][5][10]

For traders, the near-term catalysts are meteorological rather than macro: the Observatory’s short-range forecast updates, rainfall timing, cloud cover, and any tropical disturbance affecting southern China will matter most. If showers persist through the afternoon, the max can stay pinned near 29°C; if skies clear early, 30°C or higher becomes more plausible. On-chain, the only direct settlement issue is whether USDC liquidity stays orderly into expiry, but broader crypto conditions can still shape positioning: a risk-off BTC/ETH move, higher perpetual funding, or whale rotation into prediction-market liquidity may affect prices without changing the weather outcome itself.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reads Highest temperature in Hong Kong on August 4? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

Which crypto markets exist on Polymarket?

Currently active markets include BTC/ETH/SOL price targets, halving dates, ETF approvals, hard-fork outcomes and Layer-2 TVL thresholds. The list updates weekly; biggest volume sits on BTC and ETH price forecasts.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.