Highest temperature in Shenzhen on July 20?

Platform comparison

Market context

Shenzhen is currently overcast at Bao’an International Airport with a temperature of 84°F (29°C) and humidity at 83%, meaning the day’s peak heat has already passed under heavy cloud cover [1]. With the settlement window closing at 12:00 UTC tomorrow, the market’s 0% YES probability reflects the physical reality that no further significant warming is possible in these conditions.

Historical data for mid-July in Shenzhen shows daytime highs typically reaching 33–35°C under clear skies, but overcast, humid conditions like today’s cap temperatures near 30°C. The current 0% pricing aligns with this pattern, as past years with similar cloud cover and humidity have never exceeded 31°C at this station, making a higher-temperature outcome statistically implausible.

Traders should monitor the final Wunderground update for the Bao’an station, which will lock in the official resolution value once the day ends. No further weather announcements or schedules are expected to alter the outcome, as the atmospheric conditions are already stable. The market resolves purely on this single data point, with USDC payouts on Polygon executing automatically once the conditional tokens settle based on the recorded Celsius value.

Sources: 1

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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 PolyGram 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.