Field Guide to the San Gabriel Mountains: Current Conditions

Air Quality
Camera Images
Fire Information
Road Conditions
Trail Conditions, Bug and Snake Reports, and Plants Blooming
Weather, Sunrise and Sunset, UV Index
Weather Forecast

Current and Forecasted Air Quality

Azusa, Burbank, Glendora, Newhall, Pasadena, Pomona, Upland. Currently not active: Mt. Baldy, Mt. Wilson.
Forecasted Air Quality for all stations (#15 is San Gabriel Mountains).

Map of Ozone for greater L.A. area, including the SGM and San Bernardinos (click on California, select Los Angeles and the type of map you want, then on See The Map)

The SGM is by no means immune from poor air quality, but the air quality is vastly better than it was even 10 years ago. Generally the smog season runs from April through October, with poor air quality from about noon through 5 p.m. (the peak has been getting later as the air quality has improved). The best predictor of today's air quality is yesterday's air quality, which is given in the links. The AQMD forecasted air qualities are usually worse than what actually happens.

The opacity and color of the air is only weakly correlated with the ozone level, which is the prime pollutant, because ozone is nearly colorless. The air can be brown and yucky from nitrogen dioxides yet will not rob you of lung capacity. On the other hand, the air can be pristinely clear, yet have high enough ozone levels to leave you gasping for air as you hike. A hiker is impacted at lower levels of ozone than someone who is not exercising. For more information, see the AQMD's Smog and Health.

If you can't see the haze layer below you, you're in the smog zone. Worse, the smog tends to be worst just as the top of the haze layer, so when you are in that, you may be in a smoggier environment than anyplace in L.A. For more about the top of the haze layer, see High Temperatures in the San Gabriel Mountains.

Current Camera Images

Current Fire Information

Road Conditions

Trail Conditions, Bug and Snake Reports, and Plants Blooming

Current Weather, Sunrise and Sunset, UV Index

See also Camera Images for visual inspection of current weather.

Latest Weather Forecast

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Copyright © 1996-2005 by Tom Chester and Jane Strong.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
Comments and feedback: Tom Chester | Jane Strong
Last update: 23 February 2007