Highest temperature in Tokyo on August 14?

Platform comparison

Market context

The market centres on the peak temperature recorded at Tokyo Haneda Airport on 14 August 2026, with settlement determined by Weather Underground's Daily Observations table rather than summary figures. The 0% implied probability suggests traders expect the temperature to fall outside the upper range bracket being priced, or that consensus has clustered heavily toward lower temperature bands.

Tokyo's August temperatures show consistent patterns across decades. Mid-August typically registers highs between 32–35°C, with extreme readings above 36°C occurring roughly once every three to five years during particularly intense heat waves. The 2010 heat wave saw Tokyo reach 39.9°C in early August, whilst 2023 peaked at 37.5°C mid-month. Historical frequency data indicates that temperatures exceeding 37°C on any given mid-August date occur in approximately 15–20% of years, suggesting the crowd's 0% reading reflects either extreme confidence in a cooler-than-average outcome or mispricing of tail-risk scenarios.

Traders should monitor Japan Meteorological Agency forecasts released in early August 2026, particularly alerts regarding Pacific high-pressure systems and potential typhoon activity that could suppress temperatures. La Niña or El Niño conditions entering northern hemisphere summer will influence regional atmospheric patterns. Recent precedent from 2024–2025 heat seasons showed forecasters increasingly accurate at 10–14 day horizons, though sudden shifts in upper-level wind patterns remain difficult to predict. The settlement window closes midday on the 14th, allowing only morning observations to influence final resolution, which compresses the information window compared to full-day markets.

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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%.