Highest temperature in Chongqing on August 10?

Platform comparison

Market context

Chongqing Jiangbei International Airport is set up for a very hot August day, and the practical question for a trader is whether the station’s **Daily Observations** peak lands in the 33°C, 34°C or 35°C band rather than the broader city forecast. Polymarket’s market page currently shows the crowd leaning to **35°C** at 41% and **34°C** at 36%, with model guidance pointing to a daytime maximum near 34–35°C and AccuWeather’s Chongqing forecast showing about 95°F/35°C for the date.[2][12] The 0% implied YES price is hard to square with those published forecasts, so the gap is more likely a market-structure artefact than a true read on weather.

For calibration, Chongqing’s August climatology is already extreme: multiple climate sources describe August as the hottest month, with typical highs around 34°C and historical spikes into the low 40s Celsius.[3][9][13][17] That means a programmatic approach would usually anchor on the distribution of late-summer daily maxima, then stress-test for convective cloud cover or thunderstorm timing that can cap the airport reading. Because settlement depends on the highest temperature in Weather Underground’s **Daily Observations** table, a bot or conditional order system should watch the station feed itself, not the day-high summary, and should treat the first published observation for the following date as the cut-off for revisions.[2]

The main catalysts are the local forecast updates, the timing of any thunderstorms, and whether the airport site records a brief afternoon spike before precipitation or cloud cover builds.[12][15] AccuWeather already flags a couple of thunderstorms and high humidity, which matters because a short-lived pre-storm maximum can settle the band even if the official forecast looks only marginally cooler.[12][15] For automation, the useful trigger is not a single forecast number but the sequence of hourly updates versus the observed station trace: if the airport has already printed near-35°C readings before noon UTC, the market is effectively trading the odds of another marginal overshoot later in the day.[2][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Chongqing on August 10? 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

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.

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%.