Highest temperature in Shenzhen on July 21?

Platform comparison

Market context

Shenzhen is currently experiencing overcast skies with 83% humidity and a RealFeel temperature of 95°F, while forecasts indicate a 90% chance of precipitation for the Bao'an International Airport area [1][2]. This immediate wet weather acts as a natural suppressor for peak heat, directly supporting the crowd-implied 0% probability that the temperature will breach the highest threshold in the market’s resolution ranges. The consensus correctly identifies that heavy cloud cover and rain on 21 July 2026 will prevent the extreme solar heating required to hit the top bracket, making the favourite the lower temperature ranges.

Historical data for late July in Shenzhen typically sees highs between 31°C and 34°C, but persistent monsoon activity often caps temperatures near 30°C or lower [1]. Comparable cases from previous wet July days show that when precipitation probability exceeds 80%, peak temperatures rarely exceed 32°C, validating the current pricing as efficient rather than offering obvious contrarian value. Traders should watch the hourly precipitation updates and cloud cover density at the Bao'an station, as any sudden clearing could theoretically shift the odds, though the 90% rain forecast makes this a low-probability catalyst [2]. No further announcements or schedule dependencies exist beyond the real-time Wunderground data that will settle the market.

Sources: 1 · 2

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 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.