Highest temperature in Shenzhen on August 11?

Platform comparison

Market context

On 11 August 2026, the highest temperature recorded at Shenzhen Bao'an International Airport will determine the settlement of this market. The resolution hinges on the Daily Observations table from Weather Underground rather than the Day High & Low summary section—a distinction that matters when automated systems and manual corrections diverge. Shenzhen's August climate typically peaks between 32–35°C, though extreme heat events have pushed readings toward 37–38°C in recent summers.

Historical August records for Shenzhen show considerable year-to-year variation. The city experienced a 37.3°C high in August 2022 and 36.6°C in August 2023, whilst cooler years have settled around 33–34°C. This volatility explains why the 0% crowd probability appears miscalibrated; traders on Polymarket, Kalshi, and Betfair typically assign meaningful probability mass to temperature ranges spanning 32–36°C in mid-August. Kalshi's regulatory constraints limit US-based traders' access to weather derivatives, whilst Betfair and Smarkets offer tighter decimal odds on granular temperature bands. Polymarket's fee structure and global reach have attracted deeper liquidity on comparable weather markets, though implied probabilities across platforms often reflect identical underlying meteorological forecasts.

Traders should monitor the Asian summer monsoon pattern through July and early August 2026, particularly tropical cyclone activity in the South China Sea, which can suppress daytime highs. China Meteorological Administration forecasts, released fortnightly, will provide the most reliable directional signal. The settlement window closes at 12:00 UTC on 11 August, requiring traders to account for the airport station's local time zone (UTC+8) when interpreting intraday temperature movements.

Methodology

We read Highest temperature in Shenzhen on August 11? 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.

Which platform is accessible globally?

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

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.