The inland setting means local environmental conditions are shaped more by urban density than coastal influences.
In line with average conditions across San Francisco
24-Hour AQI Trend
Pollutant Breakdown
Peer Comparison
In line with average conditions across San Francisco
Why San Francisco's Air Is What It Is
San Francisco sits in an inland urban setting where local environmental conditions are shaped primarily by density and development patterns. Temperature swings between day and night can be more pronounced than in coastal areas.
Historical Context
Current AQI of 31 reflects recent monitoring data. Local conditions can shift with weather patterns, traffic volume, and seasonal factors.
24-Hour Hourly Forecast
Best window: 05:00 (AQI 31) · Peak AQI: 41 at 21:00
| Time | AQI | Temp (°F) | Humidity | Wind (mph) | PM2.5 | PM10 |
|---|---|---|---|---|---|---|
| 00:00 | 36 | 127.0 | 70% | 8.7 | 9.5 | 14.8 |
| 01:00 | 35 | 126.7 | 71% | 5.1 | 8.8 | 13.5 |
| 02:00 | 34 | 126.3 | 70% | 1.6 | 8.1 | 12.5 |
| 03:00 | 33 | 126.0 | 66% | 5.1 | 7.8 | 11.9 |
| 04:00 | 32 | 124.7 | 69% | 3.9 | 7.8 | 12.0 |
| 05:00 | 31 | 124.0 | 71% | 4.8 | 7.1 | 10.9 |
| 06:00 | 31 | 123.6 | 75% | 1.8 | 6.8 | 10.2 |
| 07:00 | 31 | 126.5 | 72% | 3.5 | 6.3 | 9.5 |
| 08:00 | 31 | 132.1 | 72% | 3.0 | 6.1 | 9.4 |
| 09:00 | 31 | 136.2 | 64% | 3.4 | 6.2 | 9.5 |
| 10:00 | 31 | 138.4 | 60% | 5.7 | 6.7 | 10.2 |
| 11:00 | 31 | 141.6 | 59% | 7.3 | 6.7 | 10.1 |
| 12:00 | 32 | 143.1 | 59% | 8.7 | 6.6 | 10.1 |
| 13:00 | 32 | 144.9 | 58% | 9.3 | 6.7 | 10.3 |
| 14:00 | 33 | 145.0 | 57% | 10.3 | 6.7 | 10.4 |
| 15:00 | 34 | 145.9 | 56% | 9.6 | 6.5 | 10.0 |
| 16:00 | 36 | 145.0 | 58% | 9.8 | 5.8 | 8.9 |
| 17:00 | 37 | 147.0 | 57% | 7.8 | 5.1 | 7.7 |
| 18:00 | 38 | 153.5 | 38% | 6.5 | 5.7 | 8.6 |
| 19:00 | 39 | 160.0 | 14% | 10.2 | 6.0 | 8.8 |
| 20:00 | 40 | 153.3 | 18% | 8.1 | 6.5 | 9.7 |
| 21:00 | 41 | 150.6 | 17% | 8.9 | 5.9 | 8.6 |
| 22:00 | 41 | 147.6 | 18% | 8.3 | 5.5 | 7.8 |
| 23:00 | 41 | 145.2 | 20% | 8.5 | 5.1 | 7.1 |
Air quality is forecast to be good for most of the day. Great time for outdoor activities!
San Francisco's forecast helps residents make the most of their day. The cleanest air is expected during 05:00 (AQI 31) with AQI as low as 31 at 05:00. The most challenging conditions are forecast for 21:00 (AQI 41) when AQI peaks at 41 at 21:00. For those who work outdoors in San Francisco, the forecast provides important advance information. Those who work outdoors may choose to incorporate forecast data into their daily awareness routine.