Highest temperature in Shenzhen on August 4?

Platform comparison

Market context

Polymarket is pricing the highest temperature at Shenzhen Bao’an International Airport on 4 August at a **0% YES** probability today, even though the contract settles on the day’s recorded maximum from the airport station and pays out in USDC via Polygon conditional tokens. In practical terms, traders are treating every listed temperature band as unlikely at the current screen, so the market is functioning more like a low-liquidity scoring exercise than a broad weather consensus.

For context, Shenzhen’s August climate is typically hot, humid and rain-prone, with multiple sources putting average daytime highs around **31–32°C** and frequent showers. That means the realised peak often depends less on the monthly average than on whether cloud cover and rain hold through the warmest part of the afternoon; comparable forecasts for early August commonly cluster near the low 30s rather than the mid-30s, which is the sort of range that usually determines which bucket wins in these temperature markets. Recent published guidance from weather services also points to frequent rain and humidity in Shenzhen during August, supporting the idea that the upside can be capped on wetter days. [3][4][8][18][19][20]

A trader watching this contract should focus on the intraday forecast path for Shenzhen, not just the morning reading, because the settlement source is the highest value recorded on the day at the airport station, with revisions possible until the next day’s first datapoint is published. That makes afternoon convection, passing showers, and any typhoon-related disruption the main catalysts, alongside the timing of local weather updates from services such as AccuWeather, BBC Weather and the Met Office; if a strong shower band arrives near peak heating, the maximum can land a full degree or two below a drier scenario. The current spot observations already show the sort of warm, humid setup that can swing quickly with cloud and rain. [6][7][11][15]

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

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

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.

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 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.