Highest temperature in Shenzhen on August 10?

Platform comparison

Market context

Polymarket is pricing this Shenzhen heat contract at **0% YES** right now, so the market is treating a qualifying high as effectively off the board even though the USDC-settled position still resolves to a specific Celsius range on Polygon via conditional tokens. The real-world event is simple enough: the highest temperature recorded at Shenzhen Bao’an International Airport Station on 10 August 2026, with Weather Underground’s **Daily Observations** table controlling settlement if it differs from the summary high.

That 0% reading sits against a very hot seasonal baseline. Shenzhen’s August averages are around 32°C/89°F, with historical highs commonly in the mid-30s Celsius and recent forecast products pointing to a very warm day: Polymarket’s own market page cites external forecasts in the 35–36°C band, while AccuWeather and Timeanddate both show highs near 97°F, or about 36°C.[8][10][12][17] Recent history also supports that kind of outcome, with nearby August readings already running in the 35–37°C range and Weather Underground’s Bao’an history showing late-summer highs close to 98°F/36.7°C.[5][6]

For traders, the main catalysts are the day’s intraday temperature path, cloud cover, wind, and any showers that cap the peak before the settlement cut-off. Weather Underground’s rule matters because the market can settle on the **highest observed datapoint** in the observations table, not the headline day-high figure, and Polymarket says revisions count until the first datapoint for the following date appears.[8] In practice, the relevant watchpoints are the observation cadence at Bao’an Airport, the timing of any late-afternoon convective rain, and whether the station records a brief spike above the currently implied range before 12:00 UTC.

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

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.

UK Frequently Asked Questions

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

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.