Highest temperature in Hong Kong on May 22?

Platform comparison

Active sub-markets

Market context

Hong Kong’s official afternoon maximum for 22 May will be taken from the Hong Kong Observatory’s final “Daily Extract”, which matters because this market does not settle on a live reading but on the published absolute daily max once the data are finalised. Early market pricing at 0% YES implies traders are currently treating a qualifying outcome as unlikely, but the relevant range is still entirely weather-dependent until the Observatory locks in the figure.

For context, Hong Kong is already in its late-spring warm-up, with May typically producing average highs around 29°C and occasional pushes into the low 30s, especially towards month-end. The Observatory’s long-run May rankings show the month can deliver much stronger heat than the seasonal average, with record monthly mean maximums above 31°C in some years. That means a reading in the upper 20s is normal, while a 30°C-plus outcome is not exceptional if skies are bright and the air mass is warm.

For traders, the main catalysts are the day’s cloud cover, rainfall, and any southerly or easterly flow affecting the territory before the 12:00 UTC settlement cut-off. Hong Kong Observatory updates, nearby regional forecasts, and any convective showers moving in from Guangdong are the key inputs; if the day turns humid and sunny, the maximum can rise quickly, while cloud and rain suppress it. Because settlement is in USDC on-chain, the market will only move with weather expectations and the final Observatory publication, not with spot BTC or ETH unless broader crypto risk sentiment affects liquidity and pricing.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — are listed with their platform attributes, because they operate off-chain and a 1:1 comparison of contract mechanics isn't possible.

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

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

What does it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.

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.