Highest temperature in Shenzhen on July 20?

Platform comparison

Market context

Shenzhen will experience its peak July heat today, with the Shenzhen Bao'an International Airport Station recording the day’s highest temperature that determines this contract’s outcome. The settlement hinges on a single Celsius reading from Wunderground for 20 July 2026, capturing the city’s typical subtropical intensity under the influence of the subtropical high and potential typhoon activity.

Historical July data shows Shenzhen’s daytime average sits near 32°C, with frequent highs reaching that mark or slightly above across 17 rainy days in the month [2]. Given the 0% crowd-implied probability for any specific outcome, the market appears to treat the event as either a near-certainty for a different range or reflects a lack of liquidity rather than genuine doubt about extreme heat, as July is consistently the hottest month in the region [2]. Comparable cases from recent years confirm that temperatures rarely dip below 29°C during midday, making lower-range outcomes statistically improbable.

Traders should monitor real-time updates from AccuWeather and Wunderground for the exact peak reading, noting current overcast conditions with 83% humidity and a RealFeel of 95°F (35°C) [1]. While no specific weather announcements are scheduled for today, the dependency on the subtropical high and potential typhoon systems remains the primary catalyst; any sudden shift in wind patterns or cloud cover could alter the final temperature. The divergence between the 0% implied probability and the historical 32°C average suggests a significant mispricing or a technical error in the market’s odds display, warranting cross-platform verification against other sportsbook lines for similar weather contracts.

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.

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 Best Prediction Markets trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.