Highest temperature in San Francisco on August 13?

Platform comparison

Market context

San Francisco's peak temperature on 13 August 2026 will be measured at the airport weather station and resolved against Weather Underground's Daily Observations table rather than its summary display—a distinction that matters when automated systems occasionally diverge. The current 0% implied probability suggests traders are either absent from this market or treating August temperatures in San Francisco as too predictable to warrant positions. Historical August highs at SFO cluster between 75°F and 82°F, though the station has recorded readings above 85°F in roughly one year per decade during the summer months.

The resolution methodology creates a technical dependency worth noting: Weather Underground's Daily Observations table logs sub-daily readings, meaning the highest recorded temperature could differ from the official National Weather Service daily high if timing or measurement protocols shift. Traders comparing this market across platforms will notice Polymarket's decimal odds format against Kalshi's binary structure; Betfair and Smarkets typically offer tighter spreads on weather markets but require different KYC documentation depending on jurisdiction. The National Weather Service issues heat advisories when conditions warrant, though August 2026 forecasts remain unavailable until late July.

Seasonal patterns favour moderate temperatures: the Pacific's cooling influence typically caps August peaks in San Francisco, and marine layer intrusion often suppresses afternoon highs. However, atmospheric rivers or heat domes tracking inland could shift outcomes materially. Traders should monitor NOAA's extended outlooks from mid-July onwards and cross-reference any NWS advisories issued within 48 hours of the settlement date, as these often precede measurable departures from climatological norms.

Methodology

This page compares Highest temperature in San Francisco on August 13? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.