Highest temperature in Tokyo on August 7?

Platform comparison

Market context

Tokyo’s outcome depends on the highest **observed** temperature at Haneda Airport Station, with the Wunderground Daily Observations table, not the summary high/low box, controlling if the two differ. That makes the market more like a station-specific weather data contract than a general “Tokyo” temperature bet, so platform differences matter: Polymarket-style markets quote a direct implied probability, while Kalshi and Smarkets typically present prices in cents or decimal terms, and Betfair in exchange odds with commission layered on top.

The current 0% YES implies the crowd is treating the target range as very unlikely, but Tokyo’s August climatology makes that hard to read as a true zero rather than a thin market. JMA daily data for Tokyo shows highs already in the mid-30s Celsius early in the month, while July reporting noted Japan’s first “brutally hot” days of the year, including 40C readings in central regions, underscoring that extreme heat remains plausible in summer even if Haneda itself usually tracks below inland hotspots.[1][16] August guides from travel and weather sites put Tokyo’s typical highs around 31C, with peaks often above 30C and occasional spikes into the mid-to-high 30s.[4][5][12][14]

The key catalysts are the day’s actual weather evolution, not scheduled announcements: cloud cover, sea-breeze strength, rainfall, and any broader heatwave pattern across Kanto will drive the station maximum before the 12:00 UTC settlement window closes. For traders comparing books, that means the same forecast can look different across venues because of contract granularity, fee drag, and access: Betfair and Smarkets charge commission on winnings, Kalshi is fee-based in a different way, and KYC reach can be narrower or broader depending on jurisdiction, which affects who can even participate in a Tokyo weather line.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Tokyo on August 7? 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 Polymarket Alternative, 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 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. Polymarket 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.

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.