Highest temperature in Guangzhou on August 4?

Platform comparison

Market context

Guangzhou Baiyun Airport’s 4 August maximum is the settlement datapoint, so the practical question is whether the day’s top reading lands in the band that market makers have priced. On a midday UTC timetable, the relevant local afternoon is already underway in Guangzhou, which means intraday convection, sea-breeze effects and any thunderstorm outflows can still move the final high materially before the Wunderground closeout. Guangzhou’s August climatology is firmly hot and humid, with typical highs around 33°C and averages in the high 20s to low 30s, while forecast pages for early August 2026 cluster around 31–33°C and show rain risks on the day.[1][2][10][15][19]

The 0% YES print is most naturally read as a data-or-odds artefact rather than a true statement that the airport cannot touch the target band, because comparable August guidance still places Guangzhou well within a summer heat regime.[1][17][18] For a programme-driven approach, the cleanest workflow is to monitor the airport station feed, then map the reported daily maximum into the market’s Celsius bands only after the final Wunderground daily history update. That matters because nearby weather products can show materially different hour-by-hour paths, and the market resolves specifically on the station maximum, not the city average or a forecast high.[6][8][13]

For catalysts, the main variables are the afternoon rain timing, cloud cover and thunderstorm coverage in Guangdong, all of which can suppress or delay the day’s peak if showers arrive early enough.[2][6][8] Official regional forecasts published on 3 August still showed Guangzhou at 25–31°C with rain, implying a modest ceiling but not a cold outcome.[8] A trader using bots or conditional orders would therefore key off the latest airport observation sequence and any updated municipal or national forecast bulletins, rather than broader travel-site averages, because those are the inputs most likely to shift the realised maximum into or out of the relevant range.[8][16]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Guangzhou on August 4? 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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Review UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.