Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The real-world event is the peak daily temperature recorded at Tokyo Haneda Airport on 30 June 2026, measured in degrees Celsius. Historical data shows Haneda’s June highs typically range from 24°C to 28°C, with the average high near 26°C. The hot season begins around 29 June, but extreme spikes above 35°C are rare in early summer; Japan’s record high of 41.2°C occurred in Tamba City in July 2025, not Tokyo. This context explains why the crowd-implied probability of 0% for a “high” temperature outcome is rational: no credible forecast suggests Haneda will breach 35°C on this date.

Traders should monitor the Japan Meteorological Agency’s daily heatwave bulletins and any sudden shifts in the Pacific high-pressure system, which can amplify temperatures. Recent reports note Tokyo hit 36.4°C in late June 2025, marking the highest June reading in 147 years, but such extremes remain outliers. On Polymarket, odds are quoted as decimal values, while Kalshi and Betfair use implied probabilities and fixed-odds formats respectively; fee structures also diverge, with Smarkets charging lower maker fees but requiring KYC for all users. These platforms differ sharply in how they price low-probability weather events, affecting liquidity and settlement clarity for this market.

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Methodology

This page compares Highest temperature in Tokyo on June 30? 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

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.

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.

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.

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.