SEVERE WX : Air Stagnation Advisory View Alerts

How to Estimate Air Quality Only Using Your Eyes

The 5-3-1 index can help you understand and estimate the air quality at any time, from any location.

Posted: Jul 23, 2018 7:52 PM

MEDFORD, Ore. -- Wildfires are burning in remote areas, sending smoke across almost all of southern Oregon.  While the Department of Environmental Quality monitors air pollution throughout the state, not every community has an official monitoring station. Even where there is an air quality monitoring site, smoke levels can rise and fall more rapidly than the monitoring sites can update.  Those are reasons why experts recommend visual observations for air quality health alerts.

Experts say the "5-3-1 visibility index is a simple way of estimating smoke levels and what precautions to take." While this method can be a useful tool, it's not 100% accurate.  You start by determining how many miles you can see, based on your knowledge of the distance to a mountain, signage, or other landmark. The DEQ suggests "a general rule of thumb: if you can clearly see the outlines of individual trees on the horizon it is generally less than five miles away."  They recommend positioning yourself so the sun is behind you.

Once distance has been determined, follow this simple guide:

5

If visibility is well over five miles, the air quality is generally good.

Even if visibility is five miles away but generally hazy, air quality is moderate and beginning to deteriorate, and is generally healthy, except possibly for smoke sensitive persons. The general public should avoid prolonged exposure if conditions are smoky to the point where visibility is closer to the 5-mile range.

If under five miles, the air quality is unhealthy for young children, adults over age 65, pregnant women, and people with heart and/or lung disease, asthma or other respiratory illness. These people should minimize outdoor activity.

3

If visibility is under three miles, the air quality is unhealthy for everyone. Young children, adults over age 65, pregnant women, and people with heart and/or lung disease, asthma or other respiratory illness. These people should minimize outdoor activity.

1
If under one mile, the air quality is unhealthy for everyone. Everyone should avoid all outdoor activities.

No matter how far you can see, if you feel like you are having health effects from smoke exposure, take extra care to stay inside or get to an area with better air quality. You should also see your doctor or other health professional as needed.

Oregon Coronavirus Cases

Data is updated nightly.

Cases: 392197

Reported Deaths: 5186
CountyCasesDeaths
Multnomah60432839
Washington42082398
Marion39986507
Clackamas32861382
Lane30179358
Jackson24956361
Deschutes23639185
Umatilla15135182
Linn14704179
Douglas13438292
Josephine10201246
Yamhill9787143
Klamath9072147
Polk8248102
Benton611138
Malheur592790
Coos5693107
Columbia433356
Jefferson420866
Lincoln363852
Union339255
Crook336356
Wasco317046
Clatsop262735
Baker220833
Tillamook217045
Hood River214537
Morrow197825
Curry192439
Harney119933
Grant108515
Lake105616
Wallowa76013
Sherman1913
Gilliam1854
Wheeler1141
Unassigned00

California Coronavirus Cases

Data is updated nightly.

Cases: 5087907

Reported Deaths: 74561
CountyCasesDeaths
Los Angeles152858627184
San Diego4074794340
Riverside3880835358
San Bernardino3748555967
Orange3346265736
Sacramento1684922447
Kern1578751804
Fresno1568972259
Santa Clara1522681929
Alameda1252361507
San Joaquin1076041834
Ventura1040841191
Contra Costa1038691046
Stanislaus915481417
Tulare861371099
San Francisco56931672
San Mateo56354629
Monterey52521626
Solano47693358
Santa Barbara47345553
Merced45086668
Sonoma43207412
Placer42204470
Imperial38516773
Kings35221362
San Luis Obispo31511360
Madera26233311
Shasta26113458
Butte25476318
Santa Cruz22268224
Yolo21590260
Marin18495249
El Dorado18325166
Sutter14577186
Napa13424105
Yuba1076389
Tehama10282130
Humboldt10183119
Nevada10029105
Mendocino857799
Lassen797656
San Benito782979
Tuolumne774691
Lake7046110
Amador578366
Siskiyou475855
Glenn457436
Calaveras442288
Del Norte376942
Colusa325921
Inyo256746
Plumas19397
Mono18924
Mariposa160718
Trinity99817
Modoc7725
Sierra2180
Alpine1080
Unassigned810
Out of CA00
Medford
Cloudy
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Hi: 46° Lo: 38°
Feels Like: 44°
Brookings
Partly Cloudy
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Crater Lake
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