Highest temperature in San Francisco on August 5?

Platform comparison

Market context

The relevant real-world event is the warmest reading recorded at San Francisco International Airport on 5 August 2026, which Wunderground uses as the settlement reference for the market. That makes the contract a pure terminal-day temperature bet rather than a forecast of the afternoon high in the city centre, and it means late-session revisions only matter until the first data point for 6 August is published.[3][2]

The 0% crowd-implied price for the YES side should be read cautiously: August in San Francisco is usually mild, with long-run daytime highs around 20°C/68°F to 21°C/70°F, so the market’s wide set of bins still leaves room for a normal summer outcome rather than an extreme one.[1][10][14] Comparable pricing on Polymarket has also clustered around the low-70s Fahrenheit for this event, with the 72–73°F bin previously shown as the front-runner, which suggests traders have been treating the airport high as likely to land near seasonal norms rather than below them.[2]

From a regulatory and access angle, the main frictions are jurisdictional rather than weather-specific. German GlüStV rules can affect whether residents can access prediction markets at all, while the US CFTC’s reach matters because temperature contracts can sit uncomfortably close to regulated derivatives when offered to US persons. “No-KYC up to $1,500” generally means a user can trade up to that cumulative threshold without identity verification, which lowers onboarding friction for small positions but does not remove geoblocking, residency checks, or any platform-specific limits on who can participate in this specific market.[2]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This overview of Highest temperature in San Francisco on August 5? 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.