Ravalli County Air Quality

RAVALLI COUNTY AIR QUALITY

Air Quality Hotline (406) 375-6577

(Updated M-F, 8 a.m. to 5 p.m.)

Because smoke conditions can change rapidly, it is best to use the Smoke Visibility Index for your specific location.

Smoke Visibility Index

Visibility Range (Miles)

Effect

Cautionary Statement

>13.4 +

Good

No health impact

13.3 - 8.8

Moderate
Unusually sensitive people should consider limiting prolonged outdoor exertion

8.7 - 5.1

Unhealthy for Sensitive Groups

Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion

5.0 - 2.2

Unhealthy

Active children and adults and people with respiratory disease, such as asthma, should avoid prolonged exertion; everyone else, especially children, should limit prolonged outdoor exertion

2.1 - 1.3

Very Unhealthy

Active children and adults and people with respiratory disease, such as astham, should avoid outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion

< 1.3

Hazardous

All children and adults should avoid or limit all outdoor exertion

The procedure for making personal observation to determine the forest fire smoke index value for local areas without National Weather Station (NWS) or Department of Environmental Quality (DEQ) monitors is:

1. Face away from the sun.

2. Determine the limit of your visible range by looking for targets at known distances (miles).

3. Visible range is that point at which even high contrast objects totally disappear.

4. Use the values above to determine the local forest fire smoke category.

*See Homepage for Today's Air Quality Rating

Last updated 9/26/2012 11:50:33 AM by Bates, Gerry