Hour-by-hour environmental exposure forecast for San Francisco. Know when to go out and when to stay in.

Air Quality Index 28
Temperature130.1°F
Humidity79.0%
Wind Speed1.4 mph
NOTICE: Safety and air quality are subjective and fluctuate in real-time. This report is a data-driven starting point. Always exercise personal judgment, stay aware of your surroundings, and consult official local law enforcement or health department resources for real-time safety and health advice.
Good 28 AQI · Total Lung Freedom Updated: May 17, 1:29 PM

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

AQI trend chart — current reading: 28 (Total Lung Freedom). May 17, 1:29 PM.

Pollutant Breakdown

PM2.5 5.80 µg/m³ Fine particulate matter — penetrates deep into lungs
PM10 8.30 µg/m³ Coarse particulate matter — dust and pollen
NO₂ 2.20 ppb Nitrogen dioxide — traffic and combustion marker
O₃ 70.00 ppb Ground-level ozone — forms in sunlight from pollutants

Peer Comparison

In line with average conditions across San Francisco

San Francisco
28

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 28 reflects recent monitoring data. Local conditions can shift with weather patterns, traffic volume, and seasonal factors.

24-Hour Hourly Forecast

Best window: 06:00 (AQI 27) · Peak AQI: 50 at 22:00

TimeAQITemp (°F)HumidityWind (mph)PM2.5PM10
00:0033133.268%3.78.613.0
01:0032131.972%3.98.112.0
02:0031131.964%3.67.611.3
03:0029131.273%2.47.410.9
04:0028130.676%2.27.310.7
05:0028129.977%1.86.89.8
06:0027130.176%2.06.39.0
07:0027129.684%3.45.88.1
08:0027129.481%0.95.68.1
09:0027129.282%1.85.78.2
10:0028129.980%1.15.88.3
11:0028130.677%2.15.88.3
12:0028132.670%6.55.78.1
13:0029134.265%7.45.57.9
14:0032135.163%9.25.27.3
15:0034135.761%9.64.46.2
16:0037136.259%8.23.34.6
17:0040138.942%8.32.53.2
18:0043138.248%10.42.43.0
19:0046140.539%9.82.63.1
20:0048139.540%10.02.73.3
21:0049138.440%10.62.83.3
22:0050136.842%10.42.93.4
23:0050135.544%11.73.03.6

Air quality is forecast to be good for most of the day. Great time for outdoor activities!

San Francisco's air quality follows a daily rhythm that can help you plan outdoor activities. The forecast indicates 06:00 (AQI 27) as the optimal window, with AQI reaching its lowest at 27 around 06:00. Conditions are less favorable during 22:00 (AQI 50) when readings hit 50 at 22:00. For those with respiratory considerations in San Francisco, the forecast offers valuable advance notice. Air quality is forecast to be good for most of the day. Great time for outdoor activities! Consulting with a healthcare provider about personal sensitivity to the forecasted conditions may be helpful.

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Disclaimer: The information provided on this site is for informational purposes only and does not constitute professional advice. Air quality, safety, and environmental data are subject to change and may not reflect real-time conditions. Always verify with official local sources before making decisions that affect your health or safety.