Highest temperature in Tokyo on August 18?

Platform comparison

Market context

Tokyo's highest temperature on 18 August 2026 will be measured at Haneda Airport Station using Weather Underground's Daily Observations table, the primary resolution source for this market. The contract currently trades at 0% implied probability across all temperature bands, suggesting traders are either awaiting historical data or treating the event as too distant for meaningful pricing. Settlement occurs at 12:00 UTC on the resolution date, with USDC collateral locked on Polygon throughout the prediction window.

August temperatures at Tokyo Haneda typically range between 28–35°C, with the station's location near Edo Bay moderating extremes compared to inland districts. Historical August highs at Haneda have occasionally exceeded 36°C during heat waves, though sustained temperatures above 38°C remain uncommon at this coastal location. The 2010 heatwave pushed Tokyo's city-centre readings above 39°C, but Haneda's maritime influence generally keeps peaks 1–2°C lower than urban core measurements. Current market pricing at zero probability across all bands suggests either technical settlement uncertainty or insufficient trader participation this far ahead.

The Japan Meteorological Agency issues seasonal forecasts each month; the July 2026 outlook will provide the first substantive guidance on August conditions roughly six weeks before settlement. Traders should monitor whether El Niño or La Niña patterns persist into northern hemisphere summer, as these influence Pacific typhoon activity and heat dome formation over East Asia. Any significant weather system tracking towards Japan in early August would shift conditional token values materially, though Haneda's sheltered position limits volatility compared to inland prediction markets.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Alternative UK, which mirrors the Polymarket order book directly.

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 Polymarket Alternative UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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%.