Highest temperature in Tokyo on July 31?

Platform comparison

Market context

Tokyo’s daytime high is the observable event here, and the key reference point is the reading at Tokyo Haneda Airport Station rather than a citywide average. July is normally hot and humid in Tokyo, with typical daytime maxima around 29–30°C, while AccuWeather’s monthly outlook for 31 July shows about 84°F/29°C for the day and 73°F/23°C overnight, which is consistent with a summer baseline rather than an extreme-heat setup.[1][12] That matters because this market resolves to the *highest* temperature recorded on the day, so even a short-lived afternoon spike can matter more than the morning forecast.

The current crowd price of 0% YES implies the market is effectively pricing in a result below the relevant threshold bands, but that looks unusually low for a Tokyo July contract given recent Japan-wide heat. The country has just seen multiple 40°C-plus readings and even a national record of 41.2°C in Hyogo, underscoring that extreme heat is not confined to western Japan.[2][3] For comparison, a similar Tokyo temperature market for 26 July 2026 settled at 32°C, showing how these contracts can clear in the low-30s even without a major heatwave in central Tokyo.[19] On Polymarket, that would appear as an implied probability, while on Kalshi or Betfair the same view would usually be expressed through contract pricing or decimal odds, with Betfair additionally charging exchange commissions and Kalshi using its own fee model; all three also differ in KYC reach and who can access the book.

The main catalysts are local forecast updates, cloud cover, wind direction, and any heat advisory affecting the Tokyo Bay area before the noon settlement cut-off. Tokyo’s official forecast feed from the Japan Meteorological Agency is the most direct dependency for near-term trading, while Wunderground’s station history will determine the final print after the day ends.[14] For platform comparison, a trader should also note that Polymarket and Kalshi can reprice quickly as forecasts move, whereas Betfair liquidity and Smarkets spreads may be tighter or wider depending on bookmaker-style demand and regional access.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Tokyo on July 31? 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

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.

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 UK 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.