Highest temperature in Tokyo on August 17?

Platform comparison

Market context

Tokyo's highest temperature on 17 August 2026 will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table. The settlement window closes at 12:00 UTC on that date, requiring resolution within hours of the final reading. Current crowd pricing sits at 0% YES, suggesting either extreme confidence in a specific temperature band or minimal liquidity across all ranges at present.

August in Tokyo typically peaks between 32–35°C, with occasional excursions to 36–37°C during heat waves. Historical data from the Japan Meteorological Agency shows that mid-August temperatures have ranged from 28°C in cooler years to 39°C during exceptional heat events, most recently in 2023 when Tokyo recorded 37.5°C on 16 August. The 0% reading reflects either a market belief that the settlement range is extremely narrow or that traders have not yet committed capital to this specific date. Comparable August markets on crypto weather platforms typically see probability mass distributed across 3–5 temperature bands once trading activates.

Traders should monitor the Japan Meteorological Agency's seasonal forecasts and any El Niño or La Niña updates from NOAA, which influence Pacific weather patterns through summer. Real-time atmospheric pressure and humidity data from Haneda itself will become material in the final 48 hours. The resolution dependency on Weather Underground's Daily Observations table—rather than the Day High & Low summary—creates a technical arbitrage vector; traders familiar with Wunderground's data lag and station-specific quirks may identify mispricing as the settlement window approaches.

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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%.