Highest temperature in Beijing on August 4?

Platform comparison

Market context

Beijing Capital International Airport is usually in the high-20s to low-30s Celsius in early August, with forecast guides pointing to a hot, humid day and a decent chance of rain or thunderstorms limiting the ceiling on the afternoon high.[1][4][12] For this market, the key number is the *maximum observed temperature* at the airport station on 4 August, not the citywide average or feels-like reading, so traders should focus on whether the day briefly breaks into the mid-30s Celsius rather than on how warm it feels overall.[11]

The current 0% YES price looks detached from the available forecasts, which cluster around roughly 31–36°C for the date, with some sources leaning to the low-30s and others showing mid-30s highs.[2][3][4][7][10] That range matters because most outcome bands on these temperature markets are decided by a single degree, and Beijing’s August weather often mixes strong daytime heating with cloud and rain that can cap the top reading.[12][13][17] On Polymarket, the probability is shown directly in cents and moves with continuous trading, whereas Kalshi and many other regulated books quote contract prices in dollar terms that translate to implied probabilities; Betfair and Smarkets typically express this through decimal odds and usually take commission rather than embedding it in the spread.

The main catalysts are the day’s actual weather evolution at and around the airport, especially cloud cover, convective showers, and thunderstorm timing, because a late-morning or early-afternoon rain band can stop the day’s high from reaching the stronger forecast range.[4][12][17] Since the contract resolves from the Wunderground history page for Beijing Capital International Airport Station, traders should watch whether that source records an early peak before storms develop, or a later spike if sunshine persists into midday.[11] Access also differs by venue: Polymarket is broadly crypto-native, while Kalshi’s reach depends on its regulated US framework, and Betfair/Smarkets availability and fees depend on local account eligibility and market commission.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Beijing on August 4? 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

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

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.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

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. Kalshi Alternative 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.