Highest temperature in Tokyo on August 19?

Platform comparison

Market context

Tokyo's highest temperature on 19 August 2026 will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table, with settlement occurring in USDC on the prediction market platform. The current 0% crowd probability suggests either extreme confidence in a specific temperature range or minimal trading activity; given that August in Tokyo typically peaks between 32–35°C, the market structure implies traders are either heavily concentrated in one bracket or the contract has attracted limited liquidity so far.

Historical August data from Haneda shows temperatures rarely exceed 36°C on any single day, though the 2010–2020 period recorded several days above 34°C during mid-to-late August. The 0% reading on the YES side is unusual for a weather market with genuine uncertainty; it typically signals either a very narrow range has captured all probability mass, or the market has not yet consolidated around a consensus forecast. Comparable Tokyo August markets on crypto platforms have seen probability drift sharply once meteorological forecasts update 7–10 days before settlement.

Traders should monitor Japan Meteorological Agency updates and any tropical system activity in the Western Pacific, which can suppress or elevate temperatures significantly. Funding rates and whale flows on btc-prediction.bet may shift if macro volatility spikes in late July or early August, as weather markets sometimes see correlated liquidations during broader market stress. The settlement window closes at 12:00 UTC on 19 August 2026, leaving no room for post-event price discovery.

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

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

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.

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%.