Highest temperature in Tokyo on August 10?

Platform comparison

Market context

Tokyo’s outcome depends on the **single highest Celsius reading** logged at Haneda Airport in Weather Underground’s Daily Observations table, not the summary high on the page. That matters because the market resolves to a temperature band, and the current 0% YES implies the crowd is assigning effectively no chance to any band currently available on the book; on platforms such as Polymarket this is usually shown as implied probability, whereas Kalshi and Betfair more often expose a price or decimal-odds style view, so the same view of risk can look different across venues.

For context, Tokyo’s early-August highs are usually in the low- to mid-30s Celsius, with recent 10 August readings in the JMA record comfortably above 33°C and the city’s August record high at 37.7°C in the station history. Weather Underground’s Tokyo history page currently shows a high of 91°F and a low of 77°F for the day, which is broadly consistent with a hot summer profile rather than an exceptional spike. That makes the upper bands plausible only if a brief afternoon peak arrives at Haneda before the settlement window closes, but the market is still anchored to an airport station reading, not the citywide average.

The main catalysts are the daytime forecast trend, any short-lived convective heating, and the exact timestamp of the last observation before the 12:00:00Z window closes. JMA’s latest daily observation pages are the closest public cross-check for Japan, but resolution here is explicitly tied to Weather Underground, so traders should watch whether Haneda’s peak lands before midday UTC and whether later updates revise an earlier high. Platform frictions also matter: Polymarket-style markets tend to have lighter access in some jurisdictions and use fee-on-trade mechanics, while Betfair/Smarkets pricing can be affected by commission and local KYC availability, which affects where the same temperature view may be easiest to express.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Tokyo on August 10? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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.

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.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets 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.