Highest temperature in Shenzhen on August 9?

Platform comparison

Market context

Shenzhen’s peak temperature will be set by the highest reading logged at Shenzhen Bao’an International Airport Station in Weather Underground’s Daily Observations table, so a programmatic trader should key off the timestamped station data rather than the summary high/low card. As of the latest available observation, Weather Underground showed 92°F for 9 August, which is about 33.3°C and sits below the market’s hotter outcome bands, while other live forecast pages were clustering around 35–36°C for the day.[4][8][10]

For context, Shenzhen’s August climate is typically hot and humid, with average highs around 32–33°C and occasional excursions a few degrees above that when the subtropical ridge is strong.[9][11][17] That is why the current 0% crowd-implied chance on an extreme outcome should be read cautiously: these markets often mean-revert sharply if the first daytime observations come in warm and cloud cover does not limit the afternoon maximum, particularly for a coastal station where late-day heat can still build fast.[1][4]

A hands-on setup would watch the Weather Underground feed for the airport station, then compare the latest daily max to the settlement bands and any new observations published before the cut-off at 12:00 UTC. The key catalyst is whether the station posts a higher datapoint before the first reading for the following date appears, because the market rules say later adjustments after that point are excluded.[5] In practical terms, conditional orders or bot triggers should be tied to each refreshed station observation, not to the broader city forecast, because a small upward revision from 33°C into the mid-30s changes the most likely bucket materially.[2][5][18]

Sources: 1 · 2 · 3 · 4 · 5

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

Where can I trade this market with the lowest fees?

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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%.