Highest temperature in Shenzhen on July 20?

Platform comparison

Market context

Shenzhen’s July climate is dominated by subtropical highs and frequent typhoons, pushing daytime averages to 32°C while bringing heavy rainfall and 17 rainy days per month[1]. The current 0% YES probability on Polymarket suggests the crowd expects the peak temperature on 20 July 2026 to fall outside the specific range offered, likely because historical July highs rarely breach the upper thresholds traders are betting against. In comparable years, Shenzhen’s record July highs typically hover near 35–36°C, but the persistent cloud cover and rain from subtropical systems often cap daily peaks lower, aligning with the market’s bearish stance on extreme heat.

Traders should monitor the daily Wunderground feed for the Shenzhen Bao’an International Airport Station, as settlement hinges entirely on that single sensor’s maximum reading[1]. The key catalyst is the arrival or absence of a typhoon: if one approaches Guangdong before 20 July, temperatures will likely drop below 30°C due to increased cloud and rain, reinforcing the 0% probability. Conversely, a clear, dry spell under a strong subtropical high could spike temperatures toward 36°C, potentially invalidating the current pricing. No official weather announcements are scheduled, but the China Meteorological Administration’s weekly typhoon bulletins will dictate the thermal trajectory for the settlement window.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

Do I need to KYC for this market?

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