Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Kalshi vs Polymarket) Pick polygram.ink (preferred broker) |
98% | 2% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | View on Polymarket → |
Polymarket (direct) polymarket.com |
98% | 2% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | View on Polymarket → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | View on Polymarket → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | View on Polymarket → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | View on Polymarket → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| 33°C | 98% |
| 34°C | 3% |
| 29°C or below | 0% |
| 30°C | 0% |
| 31°C | 0% |
| 32°C | 0% |
| 35°C | 0% |
| 36°C | 0% |
| 37°C | 0% |
| 38°C | 0% |
| 39°C or higher | 0% |
Market context
Shanghai’s highest temperature at Pudong airport on 4 August is expected to be comfortably above the lower Celsius bands if the forecast holds, because mainstream August outlooks for the city cluster in the low-to-mid 30s Celsius. AccuWeather’s August forecast for Shanghai shows daily highs of 82°F to 92°F, or roughly 28°C to 33°C, while other travel-weather guides put August daytime maximums around 31°C to 32°C; that makes a 0% YES price look detached from the broader temperature consensus unless the market is using a much higher band or a very specific payout threshold.[1][5][8][19]
Historically, Shanghai in August is a hot, humid, and comparatively stable summer environment, which matters because the contract resolves to the *day’s maximum at the airport station*, not the citywide average. Comparable forecast pages for 4 August point to afternoon peaks around 33°C to 35°C, and even the more cautious monthly guides sit in the low 30s, implying that the main uncertainty is whether the reading lands in one adjacent range rather than anywhere near cold-weather bins.[2][3][6][10] The current crowd-implied 0% YES therefore suggests either a mispriced tail outcome or thin participation rather than an ordinary temperature distribution.
Traders should watch for updates to Shanghai Pudong airport observations and any shift in the local short-range forecast as the day progresses, because the settlement source is the Wunderground history page for ZSPD and the highest reading can change quickly with afternoon heating, cloud cover, or rainfall.[1] Forecasts in the region currently diverge a little on rain risk and peak heat, with some models flagging patchy rain and others showing clear, dry conditions; that difference matters more here than broad monthly averages because a storm, sea breeze, or early cloud build-up could cap the max temperature several degrees below the day’s modelled peak.[2][3][12]
Methodology
Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.
Resolution & payout
Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.
Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.
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 Kalshi vs Polymarket. 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.
- How fast are USDC deposits?
- Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.
- Do I need to KYC for this market?
- On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket 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.
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