Weather and seasons impact the link between outdoor and indoor air quality. Temperature, humidity, wind patterns, and the number of allergens can affect both outdoor and indoor air quality.
Temperature: When it’s hot, ground-level ozone, a major part of smog, develops. In colder months, people tend to keep windows and doors closed. This reduces air flow and leads to the buildup of indoor pollutants.
Humidity: Dampness (i.e. high humidity) promotes mold growth and increases indoor air pollutants like dust mites. On the other hand, air that’s too dry can irritate the nose, throat, and lungs and increase the risk of infections.
Wind patterns: When wind dilutes air pollutants, it improves air quality. However, strong winds can also stir up dust and allergens. This increases the amount of pollution in the air.
Seasonal allergies: As a rule, pollen levels increase during spring and early summer. This increases symptoms for sensitive people.
Inversions and air stagnation: Temperature inversions and stagnant air can trap pollutants close to the ground. This can impact indoor air quality, particularly if there isn’t much air flow.
Seasonal activities: Humans also impact outdoor and indoor air quality. Some examples include:
- Burning wood in stoves and fireplaces during the winter
- Burning crops in warm weather
- Wildfires
Knowing how weather and seasons affect outdoor and indoor air quality can help people take useful measures to maintain healthy indoor spaces. This may include adjusting ventilation, using air purifiers, or tracking local air quality conditions to make informed decisions about when to open windows or spend time outdoors.