Highest temperature in Tokyo on August 1?

Platform comparison

Market context

Tokyo’s heat on 1 August will be set by the **highest reading at Haneda Airport**, not a citywide average, so the market is really about whether the day peaks in the low, mid or upper 30s Celsius. Tokyo’s August climate is typically hot: multiple climate guides put average highs around **31°C to 34°C**, with the month described as the hottest period of the year and daily highs often above 30°C.[3][11][12][15] Against that backdrop, a crowd price implying **0% YES** looks misaligned with the normal seasonal baseline, although it may reflect the market’s exact temperature-bucket structure rather than a view that the day will be cool.[7]

Historical context points to a wide but heat-skewed distribution. Tokyo’s long-run monthly data show August average daily highs in the mid-30s in recent years, with 2025 averaging **34.4°C** for August and weather-history sources recording an all-time Tokyo high of **37.3°C** in August 1994.[10][2] For comparison, recent market coverage on Polymarket has shown traders clustering around a **35°C** outcome for the same event, with market prices expressed as implied probabilities rather than decimal odds.[7] That matters when comparing platforms: Polymarket shows direct implied probability, while Kalshi, Betfair and Smarkets typically present prices in different formats and fees can materially change the effective take-out, especially on short-dated weather markets; KYC access also varies by venue and jurisdiction.

The main catalysts are the actual temperature path through the day and any fresh official forecasts or observations ahead of the noon UTC settlement cut-off. Tokyo’s late-summer weather can move quickly with humidity, cloud cover and rainfall, so traders usually watch hourly updates rather than monthly normals; recent coverage also notes Japan’s broader trend towards more extreme summer heat, which can lift the upper tail on daily highs.[18][20] On platforms with open order books such as Betfair and Smarkets, traders often react faster to revised forecasts and live observations, whereas on Polymarket the key question is how the implied probability reprices as Haneda prints become visible and the chosen bucket becomes increasingly certain.[7]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Tokyo on August 1? 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.

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.

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.