The moment a wildfire starts near you, you'll get an instant alert and simple tips to reduce your smoke exposure.
30xSmaller than a human hair
Fine enough to reach deep into the lungs. A MERV 13 is built to capture it.
It Doesn't Stay Local
Smoke rides the wind far downwind — you can get smoky air with no fire nearby.
Simple steps to reduce indoor exposure.
During smoke events, the EPA recommends upgrading to a MERV 13 filter — or the highest-rated filter your system can handle — to help reduce the fine particles smoke brings indoors. MERV 13 is the level most home HVAC systems can run while still capturing PM2.5, the fine particulate that makes up the bulk of wildfire smoke.
Over 70,000 wildfires burn in the U.S. every year.
Wildfire smoke can travel 1,000+ miles, affecting states that aren't even near the blaze.
Exposure to wildfire smoke can worsen asthma, trigger heart issues, and lead to ER visits.
Indoor air can hold more fine particles during wildfire events unless it's properly filtered.
The EPA advises using MERV 13 filters or portable HEPA air cleaners during wildfire smoke events.
Use the live wildfire smoke tracker and upgrade your air filters today to protect your lungs and your home.
Shop Filters For Smoke Protection
Statewide Air Quality and Tips for Better Indoor Air
California’s winds and terrain make smoke conditions change quickly across the coast, valleys, foothills, and mountains. In this blog, you will learn how to check today’s statewide picture, what patterns to watch, and simple steps to keep indoor air cleaner.
Check the AirNow Fire and Smoke Map in the morning and again after wind or weather shifts.
Indoors, close windows, set HVAC to recirculate, and use the highest MERV your system can handle while keeping normal airflow. Add a HEPA purifier in the main room.
One-inch filters load fast during smoke. If your cabinet allows, use a two-inch or four-inch pleated filter for longer life.
Plan one clean air room for your family with a right sized HEPA purifier.
Replace smoke-loaded filters after conditions improve and return to your normal schedule.
Open the AirNow Fire and Smoke Map. Enter your city or ZIP code. Tap nearby monitors to view AQI and PM2.5. Use the time slider to see expected changes through the day, then recheck in the afternoon when winds often shift.
Offshore events. Santa Ana and Diablo winds can move smoke from foothills and canyons toward the coast and into basins.
Central Valley inversions. At night and in the morning, smoke can sit near the surface until late morning mixing lifts it.
Coastal marine layer. Coastal neighborhoods may clear sooner than inland valleys. Verify local AQI before opening windows.
Passes and gaps. Sierra and desert gap winds can carry smoke quickly toward valley cities.
Set HVAC to recirculate and let the fan run so air passes the filter more often.
During smoke, install MERV 13 only if airflow and comfort stay normal.
Add a HEPA purifier in a bedroom or main living area and keep that door closed to create a clean air room.
Limit bath and kitchen exhaust while AQI is high, so you do not pull smoky outdoor air indoors.
If you use a window, wall, or portable AC, set it to recirculate and seal gaps around the unit. Run a HEPA purifier in the same room. Ventilate briefly only after the map shows cleaner air for several hours.
Swamp coolers bring outdoor air inside. Reduce use during smoke if possible. If you have alternate cooling, use it on “recirculate.” Keep a HEPA purifier running in the main room until AQI improves.
Keep common doors and windows closed. Run central fans on “recirculate.” Place HEPA purifiers in gyms, lounges, and mail rooms. Post the day’s AQI in the lobby and schedule maintenance for the clearest window on the map.
Post the current AQI at entry. When levels rise, reduce strenuous activities, keep doors closed, and run HVAC continuously on recirculate with the highest MERV the system supports. Add HEPA units in classrooms, studios, and meeting spaces.
If you face planned shutoffs or outages, choose a HEPA purifier that can run on a small backup power source and stock spare filters. Set up one clean air room with a door sweep or draft stopper. Keep battery lights and masks on hand.
Keep windows closed and set the vehicle to recirculate. Confirm that a cabin air filter is installed and in good condition. Plan fuel and rest stops for areas the map shows as cleaner. Avoid long idling in high AQI.
Check monthly by default. During prolonged smoke, inspect every one to two weeks and replace early if the media looks gray or matted or if airflow drops at vents. If your cabinet allows it, a two inch or four-inch pleated filter has more media and often lasts longer than a one-inch filter. Return to your normal schedule after several clear days.
Replace smoke-loaded filters.
Vacuum with a HEPA vacuum.
Wipe hard surfaces with a damp cloth.
Clean supply and return grilles.
Confirm the HVAC drain pan is clean and draining.
Choose MERV 13 during smoke if your system can keep normal airflow. Order exact-fit pleated filters in standard or custom sizes from Filterbuy. Filters are made in the USA and ship fast with free delivery. Turn on Auto Delivery so replacements arrive on schedule through California’s smoke season.
Open the AirNow Fire and Smoke Map and enter your city or ZIP code. Tap a monitor to see AQI, PM2.5, and health guidance.
Use AQI 101 or higher as your cue to limit outdoor activity and improve indoor filtration. Sensitive groups should be cautious even at Moderate.
Risk is highest from late spring through fall. Offshore wind events like Santa Ana and Diablo winds can worsen smoke even outside peak months.
Yes. Use the highest MERV your system can handle while keeping normal airflow. Many homes use MERV 11 daily and move to MERV 13 during smoke if the system supports it.
Yes. Set the system to recirculate so indoor air passes the filter more often. Keep windows closed.
Often yes. If your cabinet allows it, a two inch or four inch pleated filter has more media and usually lasts longer than a one inch filter.
Set it to recirculate and seal gaps around the unit. Run a HEPA purifier in the same room. Ventilate briefly only after the map shows cleaner air for several hours.
They pull outdoor air inside. Reduce use during smoke if possible. Use alternate cooling on “recirculate” and run a HEPA purifier in the main room.
Check monthly by default. During prolonged smoke, inspect every one to two weeks. Replace early if the media looks gray or matted or if airflow drops.
Choose one bedroom or living area. Keep doors and windows closed. Run a HEPA purifier sized for the room. Block the door gap with a draft stopper or a rolled towel.
They can help short term if built safely with a newer certified box fan and a MERV 13 filter. Do not leave them unattended.
A well fitting N95 or P100 can reduce particle exposure. Cloth and surgical masks are not designed for fine smoke.
Keep windows closed and set the vehicle to recirculate. Confirm a cabin air filter is installed and in good condition. Plan stops for areas the map shows as cleaner.
Keep common doors and windows closed. Run central fans on recirculate. Use HEPA purifiers in gyms, lounges, and mail rooms. Post the day’s AQI in the lobby.
Post the current AQI. At elevated levels, reduce strenuous activities, keep doors closed, run HVAC continuously on recirculate with the highest MERV the system supports, and add HEPA units in classrooms and meeting spaces.
