Highest temperature in Tokyo on August 4?

Platform comparison

Market context

Tokyo’s temperature is set by summer heat rather than a single discrete event, and the relevant number here is the day’s *highest* reading at Haneda Airport, which is usually several degrees above the overnight low and often sits in the low-to-mid 30s Celsius in August. Current month-ahead forecasts for Tokyo cluster around highs of roughly 31–31.5°C, with lows near 25°C, while Tokyo’s historical August averages are about 31°C maximum and 24–25°C minimum, which makes an outcome in the low 30s the baseline rather than an outlier.[1][12][16]

That is why a crowd price of 0% YES looks aggressive on the face of the weather data: even a modestly warm August day would normally clear the market’s settling ranges, and Tokyo’s recent daily maximum observations have already reached the mid-30s Celsius in early August. The more useful comparison across venues is pricing format and access: Polymarket and Kalshi quote the event as an implied probability, so the same view is shown as a percentage, whereas Betfair and Smarkets tend to present decimal odds, which can make a low-probability position look less intuitive until you convert for commission.[9][11]

For traders, the main catalysts are the near-term forecast updates, not policy headlines: the key dependency is whether Tokyo stays under persistent cloud, rain, or typhoon-influenced weather, which would cap the day’s maximum, versus a clear, humid day that allows a late-afternoon peak. Official hourly and daily updates can move quickly into the settlement window, and the market resolves off the Wunderground high for Tokyo Haneda Airport Station rather than a citywide average, so site-specific airport conditions matter more than a broader Tokyo forecast.[2][13] KYC and market access also differ by venue, with Kalshi and Betfair generally requiring more formal onboarding than Smarkets, which affects who can actually express the same weather view even when the underlying probability is similar.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Tokyo on August 4? 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 Kalshi Alternative, which mirrors the Polymarket order book at 0% fees.

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

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 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.

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. Kalshi 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.