Highest temperature in San Francisco on August 13?

Platform comparison

Market context

San Francisco International Airport will record its highest temperature on 13 August 2026, measured at the official weather station and logged in Weather Underground's Daily Observations table. The settlement window closes at midday UTC, meaning traders must rely on preliminary overnight data or early-morning updates to capture the final reading. The distinction between the Daily Observations granular record and the Day High & Low summary section is material; Weather Underground's primary data feed often contains higher precision readings that differ from rounded summary figures, a detail that has historically affected temperature-range resolutions across US airport stations.

Historical August temperatures at SFO show a median high of 72°F, with extremes ranging from 89°F (August 1993) down to 58°F (August 1986). The 0% crowd probability suggests traders are pricing in either high confidence in a narrow range or genuine uncertainty about which bracket will capture the day's peak. August 2026 falls within the typical summer pattern for the Bay Area, though Pacific water-temperature anomalies and upper-atmospheric blocking patterns—measurable through NOAA's Climate Prediction Center forecasts released in early August—will determine whether the day trends toward historical norms or outliers.

From a regulatory standpoint, this market operates under differing frameworks depending on trader jurisdiction. US traders face CFTC oversight of prediction markets, though certain weather derivatives fall outside direct regulation if structured as information contracts. The German GlüStV (gambling licensing statute) treats weather prediction markets as gaming products requiring state approval; EU traders should verify their jurisdiction's stance. Platforms offering no-KYC access up to $1,500 notional exposure typically apply this threshold per market or per account, meaning a single $1,500 position on this SFO temperature range would remain compliant under that exemption, though cumulative exposure across multiple weather markets may trigger identification requirements.

Methodology

This overview of Highest temperature in San Francisco on August 13? 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.

FAQ

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. Is Kalshi Legal in California has a different geo footprint.

Do I need to KYC for Is Kalshi Legal in California?

Not for lifetime trading volume under $1,500. Above that threshold, a quick KYC flow kicks in — ID, selfie, approximately 5-10 minutes. The threshold matches FATF travel standards for unregulated crypto platforms.

How are winnings taxed?

Tax treatment varies by jurisdiction. In most countries, prediction market gains are treated as ordinary income or capital gains. We cannot provide tax advice — consult a tax professional for your specific situation.

What happens during a tax audit?

You're responsible for documenting your trades. Is Kalshi Legal in California exports a full transaction history (CSV/PDF) for tax reporting. In an audit you'll need to present these documents.

Are prediction markets gambling?

Legally unclear in most jurisdictions. Some interpretations classify them as wagering (gambling regulation applies), others as derivatives (financial regulation applies). There's no global precedent specifically for on-chain prediction markets.