Highest temperature in Shenzhen on August 17?

Platform comparison

Market context

On 17 August 2026, the highest temperature recorded at Shenzhen Bao'an International Airport Station will fall into one of several defined ranges. The market currently prices all outcomes at 0% YES, indicating the crowd has not yet allocated meaningful liquidity to any specific temperature bracket. This reflects early-stage market formation rather than conviction about the underlying event; Polymarket's conditional token architecture on Polygon means positions remain dormant until settlement, with USDC collateral locked across the range outcomes.

Shenzhen's August temperatures have historically clustered between 28–35°C, with extreme heat occasionally pushing toward 36–37°C during particularly intense subtropical pressure systems. The 2023 summer saw multiple days exceed 35°C in mid-August, whilst 2022 recorded a peak of 36.4°C on 16 August. These precedents suggest the market's current zero-probability stance undervalues the likelihood of moderate-to-high temperature ranges, since the city's monsoon season typically delivers sustained heat during this window. Weather Underground's Daily Observations table—the designated resolution source—often records slightly different peaks than summary displays, a distinction that matters for boundary cases near range thresholds.

Traders should monitor the China Meteorological Administration's forecasts from early August 2026, particularly any alerts regarding typhoon systems or heat domes that could suppress or amplify temperatures. The Western Pacific typhoon season peaks in August, and tropical cyclone activity within 1,000 kilometres can dramatically alter Shenzhen's thermal profile. Additionally, any revision to Weather Underground's station methodology or data collection protocols before settlement could affect how the Daily Observations table reports readings, though such changes remain rare.

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

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 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.

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%.