Highest temperature in San Francisco on August 13?

Platform comparison

Market context

San Francisco's weather on 13 August 2026 will be shaped by typical late-summer conditions in the Bay Area, where coastal influence and marine layer effects generally suppress peak temperatures compared to inland regions. The market resolves on the highest temperature recorded at San Francisco International Airport Station, using Weather Underground's Daily Observations table as the authoritative source rather than summary figures.

Historical August temperatures at SFO show a median high around 72°F, with the station's all-time August record of 103°F set in 1993 representing an extreme outlier driven by rare inland heat penetration. Most years see August highs between 68–78°F, constrained by the Pacific's cooling effect and persistent morning fog that often lingers into afternoon. The current 0% crowd probability suggests traders expect temperatures to fall outside the highest-range bracket entirely, reflecting confidence in typical seasonal patterns rather than anomalous heat.

The relevant catalysts centre on large-scale atmospheric patterns developing in the weeks preceding mid-August 2026. A ridge of high pressure over the western United States, or an unusually weak marine layer, could push temperatures significantly higher than the historical norm. Conversely, a coastal low-pressure system or strengthened thermal inversion would reinforce typical cool conditions. Traders should monitor National Weather Service forecasts and Climate Prediction Center outlooks from late July onwards, as these will signal whether atmospheric setup favours above-normal or near-normal August temperatures for the Bay Area.

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in San Francisco on August 13? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

UK Frequently Asked Questions

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Are political prediction markets legal in my country?

It varies. They sit in legal gray areas in most jurisdictions. Polymarket is geo-blocked from US/UK/EU; some broker frontends have a different geo footprint. Trade only with capital you can afford to lose, and only if you understand the legal status in your jurisdiction.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.