Highest temperature in Shenzhen on August 18?

Platform comparison

Market context

Shenzhen's August heat will peak somewhere on the 18th, with the highest reading from Bao'an International Airport's official station determining the outcome. The 0% crowd probability suggests traders are either confident the temperature will fall below the lowest range option, or the market has attracted minimal activity ahead of the settlement window. August in Shenzhen typically brings sustained heat above 30°C, making extremely low readings unlikely unless unusual weather systems intervene.

Historical August temperatures at Bao'an station show daily highs consistently between 32–35°C across most years, with occasional peaks above 36°C during heat waves. The 2023 August average high was 33.2°C; 2022 saw several days exceed 35°C. These patterns suggest the market's lowest range thresholds may be set above realistic expectations, or the crowd has simply not engaged with pricing. Comparable coastal Chinese cities like Xiamen and Guangzhou show similar August profiles, rarely dipping below 31°C for daily highs.

Traders should monitor tropical cyclone activity in the South China Sea during mid-August, as storm systems can suppress temperatures significantly. The China Meteorological Administration issues 10-day forecasts routinely; any alerts for August 15–18 could shift conditions. Bao'an's measurement protocols remain consistent year-on-year, eliminating station-drift concerns. The resolution source—Weather Underground's Daily Observations table rather than summary figures—requires verification against the specific data feed, not rounded or adjusted figures.

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.

UK Frequently Asked Questions

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.

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%.