Highest temperature in Tokyo on August 11?

Platform comparison

Market context

Tokyo's highest temperature on 11 August 2026 will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table, with settlement occurring at midday UTC. The Polymarket contract currently prices this event at 0% YES across all temperature bands, suggesting traders are either awaiting clearer atmospheric modelling or treating August heat in Tokyo as sufficiently predictable that no meaningful uncertainty exists at present valuations. USDC settlement on Polygon will follow whichever temperature bracket captures the recorded high, with conditional tokens resolving accordingly once Weather Underground publishes its official data.

Historical August temperatures at Tokyo Haneda show consistent patterns: the station typically records highs between 32–35°C during mid-August, with occasional excursions above 36°C during heat waves. The 2010 heat wave pushed readings to 37.8°C, whilst more recent years (2019–2023) have seen August 11 highs cluster around 33–34°C. These precedents suggest the 0% pricing reflects baseline confidence in moderate-to-warm conditions rather than extreme outliers, though the resolution window extends to 2026, allowing substantial time for seasonal forecasting models to refine their predictions.

Traders monitoring this contract should track Japan Meteorological Agency seasonal outlooks, released quarterly, which influence medium-range temperature expectations. Pacific typhoon activity in early August could suppress temperatures, whilst persistent high-pressure systems over the Kanto region would elevate them. El Niño or La Niña conditions entering 2026 will shape broader atmospheric circulation patterns affecting East Asia, making NOAA and JMA climate advisories relevant catalysts for repricing.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Kalshi UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.