Highest temperature in Chengdu on August 17?

Platform comparison

Market context

On 17 August 2026, the highest temperature recorded at Chengdu Shuangliu International Airport will fall into one of several defined ranges. The market resolves using the Daily Observations table from Weather Underground rather than the Day High & Low summary, a distinction that matters when automated data feeds pull from different endpoints. For programmatic traders, this means validating the exact source field before settlement—mismatched data sources have caused disputes on temperature markets before, particularly when station instruments record peak readings at different times of day.

Chengdu's August climate is consistently hot and humid, with historical highs typically between 32–36°C. The 0% crowd probability suggests traders are pricing in either extreme confidence in a specific temperature band or uncertainty about which range will resolve. Comparable August days at Shuangliu show little volatility in peak temperatures across years; the station's readings cluster predictably within a 2–3°C band. This stability makes outlier outcomes (sub-30°C or above 38°C) statistically unlikely, though monsoon activity or unusual weather systems could shift patterns.

Traders should monitor China Meteorological Administration forecasts released in early August 2026, which typically provide 10–14 day outlooks for regional temperatures. Sichuan province weather alerts and any typhoon activity affecting central China would serve as leading indicators. For those building conditional orders or bots, setting triggers on official CMA announcements and cross-referencing against historical Shuangliu data patterns would help identify mispriced ranges before settlement approaches.

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'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%.