Sub-Regional Visibility 50th Percentile ("Average Visibility Days")
Sub-Regional Avg Visibility Days
Mile (miles)
The sub-regional visibility in South Lake Tahoe and the distance that the human eye can see. It is measured by using a reconstructed light extinction (Bext) value derived from an equation that combines measured concentrations of several gasses and particles. The equation is corrected for humidity and natural “background” light scattering. Bext is summarized by “average visibility days” (50th percentile values) and “worst visibility days” (90th percentile values) for each year followed by calculating the 3-year running average. This indicator measures the 3-year mean against the 50th percentile.
Extinction coefficient and distance of visibility
This Indicator is reported in the following LT Info areas:

Sub-regional visibility conditions at the old South Lake Tahoe site and current Lake Tahoe Community College site. 

No Subcategories for this Indicator.

Program Air Quality


TRPA and its partners monitor five air quality constituents (ozone, carbon monoxide, particulate matter 2.5, particualte matter 10, oxides of nitrogen) at six air quality stations located around the Lake Tahoe Basin. All air quality monitoring is conducted according to strict EPA-standards or EPA-approved equivelant methods. The six air quality stations are operated and funded by a variety of federal, state, local, and educational partners.


Associated Programs data not provided.