Highest temperature in Tokyo on July 13?

Platform comparison

Market context

Tokyo faces its peak summer heat on 13 July 2026, with the highest temperature at Haneda Airport Station set to determine the outcome of this weather prediction market. The settlement hinges on a single Celsius reading from Wunderground, capturing the day’s maximum heat before the 12:00 UTC deadline.

Historical data frames the current 0% implied probability for any specific outcome as a market anomaly rather than a meteorological certainty. July in Tokyo typically sees highs between 29°C and 32°C, with Haneda’s 2026 forecast projecting daily peaks from 76°F to 91°F (24°C–33°C) [1]. Recent national records show Japan hitting 41.8°C in 2025, yet Haneda rarely exceeds 35°C even during extreme heatwaves [3][5]. Polymarket’s active counterpart on this event assigns 37% probability to 31°C and 24% to 32°C, highlighting a stark divergence from Kalshi’s or Betfair’s likely zero-probability stance on undefined ranges [2]. This split reflects how platforms handle decimal odds versus implied probability: Polymarket uses fractional shares with 0% fees for creators, while Kalshi applies a 2% fee and requires KYC, limiting its user base compared to Smarkets’ peer-to-peer model.

Traders should monitor the Japan Meteorological Agency’s daily 09:00 JST heat advisories and real-time Wunderground updates for Haneda, as sudden shifts in cloud cover or wind could alter the peak. No official announcements are scheduled, but the agency’s weekly climate summary on 10 July may offer early signals on regional heat intensity [4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Tokyo on July 13? 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 UK, 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. 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.