Great Smoky Mountains National Park
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Ozone (O3)
Ground-level ozone (O3) measured in parts per billion (ppb) forms near the Earth's surface when volatile organic compounds react with nitrogen oxide emissions in the presence of sunlight. This is different from the ozone layer in the upper atmosphere, which protects us from harmful ultraviolet radiation. Ground-level ozone can harm both humans and plants.
CURRENT 1-Hour Average
CURRENT 8-Hour Average
- 0 ppbGood
- 55Moderate
- 71Unhealthy for Sensitive Groups
- 86Unhealthy
- 106Very Unhealthy
Air Quality Index
(ppb)
Health Concern
Good
(0-54)
No cautionary statement.
Moderate
(55-70)
Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.
Unhealthy for Sensitive Groups
(71-85)
Children, older adults, active people, and people with lung disease (such as asthma) should reduce prolonged or heavy exertion outdoors.
Unhealthy
(86-105)
Children, older adults, active people, and people with lung disease (such as asthma) should avoid prolonged or heavy exertion outdoors. Everyone else should reduce prolonged or heavy exertion outdoors.
Very Unhealthy
106+
Children, older adults, active people, and people with lung disease (such as asthma) should avoid all outdoor exertion. Everyone else should avoid prolonged or heavy exertion outdoors.
Ozone is measured in parts per billion (ppb).
Updated 08/25/2020 06:00 PM EDT
Data collected at the Purchase
Charts | Ozone Health Effects | Data Disclaimer
Air quality and weather data are typically displayed on this web page within a hour of their collection. As a result, data quality is not guaranteed for scientific and regulatory purposes. These data may be revised at a later time.
Particulate Matter (PM2.5)
Particulate matter (PM2.5) pollution includes wind-blown dust, smoke from burning fossil fuels, and smoke from forest and grassland fires. Particulate matter can affect humans and visibility.
Learn more about how particulate matter affects humans »
Learn more about how particulate matter affects visibility »
CURRENT 1-Hour Average
CURRENT 24-Hour Average
- 0 µg/m3Good
- 12.1Moderate
- 35.5Unhealthy for Sensitive Groups
- 55.5Unhealthy
- 150.5Very Unhealthy
- 250.5Hazardous
Air Quality Index
(µg/m3)
Health Concern
Good
(0-12.0)
No cautionary statement.
Moderate
(12.1-35.4)
Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.
Unhealthy for Sensitive Groups
(35.5-55.4)
Children, older adults, active people, and people with heart or lung disease (such as asthma) should reduce prolonged or heavy exertion outdoors.
Unhealthy
(55.5-150.4)
Children, older adults, active people, and people with heart or lung disease (such as asthma) should avoid prolonged or heavy exertion outdoors. Everyone else should reduce prolonged or heavy exertion outdoors.
Very Unhealthy
(150.5-250.4)
Children, older adults, active people, and people with heart or lung disease (such as asthma) should avoid all outdoor exertion. Everyone else should avoid prolonged or heavy exertion outdoors.
Hazardous
(250.5+)
Everyone should avoid all physical activity outdoors. Children, older adults, and people with heart or lung disease (such as asthma) should remain indoors and keep activity levels low. Follow tips for keeping particle levels low indoors.
Particulate Matter is measured in micrograms per cubic meter of air (µg/m3).
Data collected at the Purchase
Charts | Particulate Matter Health Effects | Data Disclaimer
Air quality and weather data are typically displayed on this web page within a hour of their collection. As a result, data quality is not guaranteed for scientific and regulatory purposes. These data may be revised at a later time.
Sulfur Dioxide (SO2)
Sulfur dioxide (SO2) is a colorless air pollutant with a pungent odor. This gas can pose a threat to human health, animal health, and plant life. The primary sources of sulfur dioxide emissions are from fossil fuel combustion and natural volcanic activity.
CURRENT 1-Hour Average
CURRENT 24-Hour Average
- 0Good
- 34Moderate
- 144Unhealthy for Sensitive Groups
- 224Unhealthy
Air Quality Index
(ppb)
Health Concern
Good
(0-33)
None
Moderate
(34-143)
Unusually sensitive people should consider reducing prolonged or heavy exertion.
Unhealthy for Sensitive Groups
(144-223)
People with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion.
Unhealthy
(224+)
People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion. Everyone else should reduce prolonged or heavy exertion.
SO2 is measured in parts per billion (ppb).
Data collected at the Purchase
Charts | SO2 Health Effects | Data Disclaimer
Air quality and weather data are typically displayed on this web page within a hour of their collection. As a result, data quality is not guaranteed for scientific and regulatory purposes. These data may be revised at a later time.
Weather
Visibility
Visual range
is reported in miles (mi) or kilometers (km). It is defined as the
greatest distance at which a large black object can be seen and
recognized against the background sky.
Visual range
is calculated from measurements of light scattering and absorption by
particles and gases.
Fine particles and gaseous air pollution affect how far and how clearly we can see to some degree in every national park.
Learn more about how air pollution affects visibility »
Weather
Information about local atmospheric conditions can be important for understanding air quality. Weather monitored in parks may include:
- Temperature
- degrees Fahrenheit (F) or Celsius (C)
- Wind
- Average hourly direction and speed in miles per hour (mph) or meters per second (m/s)
- Precipitation
- Inches per hour (in/hr) or millimeters per hour (mm/hr)
- Relative Humidity
- Percent (%)
- Peak wind speed
- Direction (North [N], South [S], East [E], West [W]) and speed in miles per hour (mph) or meters per second (m/s) of the highest hourly record
- Solar Radiation
- Watts per square meter (w/m2)
Weather
Information about local atmospheric conditions can be important for understanding air quality. Weather monitored in parks may include:- Temperature
- degrees Fahrenheit (F) or Celsius (C)
- Wind
- Average hourly direction and speed in miles per hour (mph) or meters per second (m/s)
- Precipitation
- Inches per hour (in/hr) or millimeters per hour (mm/hr)
- Relative Humidity
- Percent (%)
- Peak wind speed
- Direction (North [N], South [S], East [E], West [W]) and speed in miles per hour (mph) or meters per second (m/s) of the highest hourly record
- Solar Radiation
- Watts per square meter (w/m2)
Visibility
Yesterday:
MAX
MIN
Wind
ENE 2 mph
Temperature
62 °F
Yesterday:
70 °F MAX
59 °F MIN
Humidity
92 %
Yesterday:
98 % MAX
76 % MIN
Precipitation
0.00 in.
Total Precipitation:
0.19 in. Today
0.09 in. Yesterday
Weather Updated 08/25/2020 07:00 PM EDT
Data collected at the Purchase
Charts | Understanding Visibility | Data Disclaimer
Air quality and weather data are typically displayed on this web page within a hour of their collection. As a result, data quality is not guaranteed for scientific and regulatory purposes. These data may be revised at a later time.
Current Air Quality
Ozone (O3)
Updated 08/25/2020 06:00 PM EDT
Data collected at the Purchase
CURRENT 8-Hour Average
- 0 ppbGood
- 55Moderate
- 71Unhealthy for Sensitive Groups
- 86Unhealthy
- 106Very Unhealthy
Ozone is measured in parts per billion (ppb).
Updated 08/25/2020 06:00 PM EDT
Data collected at the Purchase
Air Quality Index
(ppb)
Health Concern
Good
(0-54)
No cautionary statement.
Moderate
(55-70)
Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.
Unhealthy for Sensitive Groups
(71-85)
Children, older adults, active people, and people with lung disease (such as asthma) should reduce prolonged or heavy exertion outdoors.
Unhealthy
(86-105)
Children, older adults, active people, and people with lung disease (such as asthma) should avoid prolonged or heavy exertion outdoors. Everyone else should reduce prolonged or heavy exertion outdoors.
Very Unhealthy
106+
Children, older adults, active people, and people with lung disease (such as asthma) should avoid all outdoor exertion. Everyone else should avoid prolonged or heavy exertion outdoors.
Particulate Matter (PM2.5)
Data collected at the Purchase
CURRENT 24-Hour Average
- 0 µg/m3Good
- 12.1Moderate
- 35.5Unhealthy for Sensitive Groups
- 55.5Unhealthy
- 150.5Very Unhealthy
- 250.5Hazardous
Particulate Matter is measured in micrograms per cubic meter of air (µg/m3).
Data collected at the Purchase
Air Quality Index
(µg/m3)
Health Concern
Good
(0-12.0)
No cautionary statement.
Moderate
(12.1-35.4)
Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.
Unhealthy for Sensitive Groups
(35.5-55.4)
Children, older adults, active people, and people with heart or lung disease (such as asthma) should reduce prolonged or heavy exertion outdoors.
Unhealthy
(55.5-150.4)
Children, older adults, active people, and people with heart or lung disease (such as asthma) should avoid prolonged or heavy exertion outdoors. Everyone else should reduce prolonged or heavy exertion outdoors.
Very Unhealthy
(150.5-250.4)
Children, older adults, active people, and people with heart or lung disease (such as asthma) should avoid all outdoor exertion. Everyone else should avoid prolonged or heavy exertion outdoors.
Hazardous
(250.5+)
Everyone should avoid all physical activity outdoors. Children, older adults, and people with heart or lung disease (such as asthma) should remain indoors and keep activity levels low. Follow tips for keeping particle levels low indoors.
Sulfur Dioxide (SO2)
Data collected at the Purchase
CURRENT 24-Hour Average
- 0Good
- 34Moderate
- 144Unhealthy for Sensitive Groups
- 224Unhealthy
SO2 is measured in parts per billion (ppb).
Ozone
Data collected at the Purchase
Air Quality Index
(ppb)
Health Concern
Good
(0-33)
None
Moderate
(34-143)
Unusually sensitive people should consider reducing prolonged or heavy exertion.
Unhealthy for Sensitive Groups
(144-223)
People with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion.
Unhealthy
(224+)
People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion. Everyone else should reduce prolonged or heavy exertion.
Visibility
Data collected at the Purchase