Highest temperature in Shenzhen on August 10?

Platform comparison

Market context

Shenzhen’s highest temperature on 10 August will be settled from the observed peak at Shenzhen Bao’an International Airport, not the rounded “day high” shown in the summary box, so traders are really betting on the airport station’s intraday maximum rather than a citywide headline. The available weather feeds for today point to another very hot day, with forecast highs around 36–37°C and observed morning temperatures already near 32°C, which makes the 36°C band the leading Polymarket outcome and helps explain why the market is not pricing a broad tail to the upside.[10][15][17][8]

Historically, Shenzhen in August clusters around the low 30s °C, with monthly average highs near 32–33°C and frequent humid, storm-prone conditions that can cap or amplify the day’s peak depending on cloud cover and rain timing.[9][12][14] On Polymarket, that profile has translated into a highly concentrated book: 36°C is marked at 88% and 37°C at 10%, while the crowd-implied 0% for YES here looks more like a venue-definition artefact than a strong weather view.[8] That matters because Polymarket quotes implied probability directly, whereas Kalshi and Betfair-style books are typically read through contract price/decimal odds and can present a different after-fee effective price; Smarkets also publishes exchange-style prices, but fees and KYC access vary by venue and jurisdiction.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Shenzhen on August 10? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.