Highest temperature in Tokyo on August 17?

Platform comparison

Market context

Tokyo's maximum 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, fixing the resolution source to historical data rather than real-time forecasts. The 0% crowd probability reflects either extreme confidence in a specific temperature band or minimal trading activity; August in Tokyo typically records highs between 32–35°C, making the underlying event predictable within narrow bounds.

Historical August temperatures at Haneda show consistent patterns: the Japan Meteorological Agency's records indicate that daily maxima rarely deviate more than 2–3°C from the 33°C seasonal mean, and extreme outliers (above 37°C or below 30°C) occur in fewer than 5% of years. This stability explains why markets on specific Tokyo summer dates often cluster probability around a narrow range. Comparable prediction markets on Japanese weather have resolved without dispute when using Wunderground's Daily Observations table, though traders should note that the distinction between that table and the Day High & Low summary section has occasionally produced minor discrepancies of 0.1–0.5°C.

From a regulatory standpoint, this market's accessibility depends on jurisdiction. Under German GlüStV rules, prediction markets require licensing; UK traders face no blanket KYC requirement up to £1,200 (approximately $1,500), though individual platforms may impose stricter thresholds. US CFTC oversight applies to binary options contracts on US persons, but weather derivatives on foreign locations typically fall outside that remit. Traders should verify their platform's specific KYC policy before wagering, as settlement disputes on temperature data—however rare—may trigger identity verification during claim processing.

Methodology

This overview of Highest temperature in Tokyo on August 17? reviews the four comparable platforms from a regulatory perspective: which is accessible in your jurisdiction, where KYC kicks in, how the platform is classified by your country of residence. Live probability is the Polymarket mid; comparison columns show regulatory status, KYC thresholds and settlement options for each platform.

Resolution & payout

On Polymarket, resolution runs on-chain via UMA Optimistic Oracle. USDC payout is instant and automatic, with no KYC. Tax treatment depends on your jurisdiction — in the US, gains are usually ordinary income; in the UK, often capital gains. Consult a tax professional for your situation.

UK Frequently Asked Questions

Is Polymarket legal in my country?

Polymarket is geo-blocked in the US/UK/EU. Actual usage via the Polymarket interface is not possible there. The legal status itself varies — many countries treat prediction markets as a gray area. Polymarket Tax UK has a different geo footprint.

Is Polymarket regulated by the UKGC?

No. Polymarket is not licensed by the UK Gambling Commission (UKGC). It is a decentralised prediction market operated under US regulation. UK traders can use it but do not benefit from UKGC dispute resolution or player protection requirements.

What are the HMRC tax rules on Polymarket profits for UK traders?

Polymarket profits are treated as cryptocurrency disposal events by HMRC. Each USDC settlement is a taxable event subject to Capital Gains Tax (CGT). For 2026/27, the CGT rate is 18% (basic rate) or 24% (higher rate). The annual CGT exemption is £3,000. Report via HMRC Self Assessment if your total crypto gains exceed £3,000 or proceeds exceed £50,000.

Does Polymarket KYC apply to UK users?

Yes. Polymarket requires KYC (Know Your Customer) verification for all users, including UK residents. You must provide a government-issued photo ID and a selfie. The process typically takes 5–10 minutes via their ID verification provider.

What is the legal difference between Polymarket and Betfair Exchange for UK traders?

Betfair Exchange is UKGC-licensed, meaning UK consumer protections apply and winnings are typically tax-free. Polymarket is not UKGC-licensed — it operates under decentralised blockchain rules. Profits from Polymarket are subject to HMRC CGT as crypto disposals. Choose based on your regulatory preference and tax situation.