Highest temperature in Chengdu on August 9?

Platform comparison

Market context

Chengdu’s peak temperature for 9 August is likely to be set by the late-morning to afternoon warm-up at Chengdu Shuangliu International Airport, with Weather Underground’s **Daily Observations** table, not the headline high/low summary, the binding source for resolution. For a programmatic workflow, the cleanest approach is to poll the station page, parse the observation rows, and track the maximum Celsius reading seen before the settlement cutoff; the market resolves to the bucket containing that figure, so the exact hour of the day matters more than the daily average. Weather history for Chengdu suggests early August typically reaches around 30–31°C, with occasional spikes into the mid-30s and an all-time August record of 41.6°C on a month basis, so today’s pricing has to be read against a genuinely hot, humid climatology rather than a cool-weather baseline.[1][14]

Comparable August 9 observations point to a fairly broad but warm distribution: Weather Journey shows a long-term average high of 30.4°C for this date and a forecast of 33.4°C for 2026, while Travel China Guide lists August 9 highs near 29.3°C in its historical day-by-day table. That makes the market’s current 0% YES impression less about a cold outcome and more about the crowd assigning negligible weight to the specific bucket that was selected; in practical terms, a trader automating this would want to compare the live Weather Underground maximum against the market’s outcome ranges, rather than relying on rounded app temperatures or third-party monthly summaries.[1][3]

The key catalysts are straightforward: any late-morning spike before 12:00 UTC, showers or convection that cap the afternoon high, and any source-structure issue on Weather Underground that changes the observed maximum. Chengdu’s published weather pages for 9 August show cloudy conditions and a forecast around 33°C, which implies a narrow band around the low- to mid-30s unless cloud cover or rain suppresses the peak further; a bot watching this market would therefore focus on the daily observation feed, not the forecast widget, and would refresh aggressively near the settlement window to catch the last update before cutoff.[4][19]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Chengdu on August 9? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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

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.

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%.