San Francisco Air Quality — Live AQI & Bay Area Outlook

San Francisco often benefits from Pacific airflow, yet Bay Area air quality varies sharply by neighbourhood and season. Bridge approaches and dense urban corridors can show elevated nitrogen dioxide, while regional wildfire smoke may push PM2.5 into unhealthy bands across the entire metro.

Summer and autumn bring the highest smoke risk when fires burn inland and winds carry plumes toward the coast. Winter temperature inversions in the broader Bay Area can also trap particles near the surface on calm days.

Live AQI and hourly forecasts are essential for planning runs, commuting, and school travel. Cleaner periods often follow onshore wind shifts; during smoke events, limiting outdoor exertion protects lungs even when the sky looks merely hazy.