Site Conditions

 Sierra Observatory Night Sky

Seeing Conditions

FWHM of only 1.0 - 1.2 arcsecond

Average seeing is 1.0 (summer) and 1.2 (winter) for the majority of the time.


N 37.07 W 119.4 degrees

Located in the center of California's Sierra Nevada Mountains.


4,610 feet

Sierra Remote is located in a "sweet spot" of seeing: high enough to be above the Inversion Layer, but not too high to prevent easy year-round accessibility to the site.

Airflow Over the Site

Laminar above 300ft unless the wind is out of the East

The site is on top of Bald Mountain that rises several thousand feet above its surrounding terrain in all directions. The prevailing Westerly wind moves smoothly over the site. There are no mountains West of the site that would cause atmospheric turbulence. This allows the airflow to be laminar over the site and allows for the best possible seeing conditions at the 4,610 foot altitude.  

Clear Nights

Approximately 237 CLEAR nights Annually

California's Central Valley has one of the highest "ratings" for clear days of anywhere in the Western United States.

Dark Skies

Measured at 21.78 magnitudes / sq arcsecond, V band

Due to its location in the Sierra National Forest, SRO has very low risk of future development or encroachment that would affect levels of light pollution.