Highest temperature in Guangzhou on July 31?

Platform comparison

Market context

Guangzhou’s airport reading on 31 July will likely be shaped by a hot, humid summer pattern rather than by a sharp one-day temperature swing. Seasonal normals put July daily highs around 33–34°C, with many sources describing the month as one of the hottest in the city and often rainy or thundery[1][2][11][17][19]. That makes the crowd’s 0% YES on an exact range market easy to read as a pricing issue rather than a climate call: the relevant outcome is the *day’s recorded maximum at Guangzhou Baiyun International Airport Station*, not the broader city forecast, so even a familiar 33–35°C afternoon can still settle into a different band if cloud cover or showers cap the peak[3][4][8].

For platform comparison, the main distinction is how this market is presented and accessed. Polymarket and Betfair typically show prices in market-native probabilities or decimal odds, while Kalshi-style contracts are usually easier to map directly into settlement bands and cents-per-contract pricing; in practice, that affects how quickly traders can compare a 0% YES quote with an exchange price on the same temperature band. Fee treatment and access also differ: Betfair and Smarkets generally impose exchange-style commissions, while KYC and country availability can be tighter on regulated venues than on more crypto-native platforms. The key catalysts to watch are late-morning and early-afternoon forecast updates, convection timing, and any thunderstorms around the airport, since Guangzhou summer forecasts commonly carry high rain probabilities and 30°C-plus readings at this time of year[4][5][7][12].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Guangzhou on July 31? 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

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

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.

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.