At 7:00 a.m., before opening a window or sending anyone outside, check the local Air Quality Index (AQI). That one habit is the backbone of a sensible wildfire smoke response. Smoke can arrive hundreds of miles from a fire, turn a clear-looking morning unhealthy by noon, and remain a problem after the smell fades.
For most households, the job is not to build a bunker or buy expensive specialty equipment. It is to reduce the smoke your family breathes, preserve the medicines and supplies that matter, and know when ordinary routines need to change. A modest indoor-air setup, a few replacement filters, and a written plan can cover the most useful ground.
Build your wildfire smoke response around the AQI
AQI is a practical decision tool, not a weather curiosity. It combines several pollutants into one number, but wildfire smoke is especially concerning because of fine particles called PM2.5. These particles are small enough to get deep into the lungs. Smoke can aggravate asthma, COPD, heart disease, and other existing conditions. Children, older adults, pregnant people, and people with lung or heart conditions need more conservative limits.
Use the AQI forecast and current reading for your immediate area. The outdoor visibility test is not reliable. Some of the most harmful particles are not obvious from a window, and a smoky smell alone does not measure exposure.
A workable household rule is to adjust activities at these levels:
- Below 100: Most normal activities can continue, though sensitive family members should watch for symptoms and limit prolonged hard exertion if smoke is noticeable.
- 101 to 150: Move kids’ sports, walks, and strenuous yard work indoors when possible. Keep windows closed and run filtration.
- 151 to 200: Treat outdoor time as necessary-only, especially for children, seniors, and anyone with respiratory or cardiac conditions.
- Above 200: Stay indoors with filtered air as much as practical. Postpone nonessential errands and check on neighbors who may need help managing medications, air conditioning, or transportation.
These are household operating rules, not a substitute for medical guidance. If someone has chest pain, severe trouble breathing, confusion, blue lips, or symptoms that are rapidly worsening, seek urgent medical care.
Write down the people-specific decisions
A smoke plan gets more useful when it names real people. On our household sheet, we note who uses inhalers, who has seasonal asthma, which child has outdoor practices, and which family member needs air conditioning to sleep safely. Put medication refill dates beside those notes.
Ask your clinician or pharmacist in advance how to handle smoke days if someone has asthma, COPD, heart disease, or another relevant condition. Do not stretch prescription medicine by skipping or reducing doses without medical advice. During a regional smoke event, pharmacies, clinics, and delivery services can be busier than usual.
Make one clean-air room before smoke season
Trying to filter every room in a typical suburban home can be expensive and disappointing. A better first move is creating one room where the family can sleep, work, and recover from outdoor exposure. Choose a bedroom, living room, or other room with few exterior doors and windows. Close windows and exterior doors, then keep the room comfortable enough that people will actually use it.
We found that the best clean-air room is not always the smallest one. A tiny spare bedroom filters quickly, but it is a poor choice if the person with breathing trouble cannot sleep there or needs help getting around. For many families, a bedroom with an attached bathroom or a living room near essential medications is more practical.
Run a portable HEPA air purifier sized for the room. Look at the unit’s smoke CADR, or clean air delivery rate, rather than marketing language alone. For a 150- to 250-square-foot bedroom, a smoke CADR around 150 or higher is a reasonable starting point. Larger rooms need more capacity, or more time with the door closed.
A dependable midrange purifier commonly costs about $100 to $250. Replacement filters can run $25 to $80 a set, depending on the model. Check replacement-filter cost before buying the machine. A cheap unit with hard-to-find filters is not a bargain after the first fire season.
Set the purifier to a higher fan speed when smoke is heavy, then lower it only if noise makes sleep impossible. Higher speed uses more electricity and makes more noise, but it cleans air faster. Keep the filter schedule written on the unit with painter’s tape. During repeated smoke events, filters may load faster than the package schedule suggests.
The low-cost fan filter option
A box fan paired with a high-efficiency HVAC filter can be a useful budget backup. We have used a 20-inch box fan with a 20-by-20-inch MERV 13 filter taped securely to the intake side. In normal retail conditions, the fan may cost $20 to $35 and a single filter about $15 to $30. A four-filter cube design can move more air, but it takes more floor space and costs more upfront.
This is not a permanent substitute for a certified air purifier, and it needs supervision. Use a newer fan in good condition, keep it away from curtains and children, do not leave it operating unattended, and replace the filter when airflow drops or it becomes visibly loaded. Never use a damaged cord or a fan that smells hot.
Keep outdoor smoke from becoming indoor smoke
Close windows, exterior doors, fireplace dampers, and fresh-air intakes that you can safely close. Avoid activities that add particles indoors: smoking, burning candles or incense, frying at high heat, and vacuuming with a vacuum that does not have effective filtration. Save wood-burning fireplaces and fire pits for another day.
Your central HVAC system can help if it is maintained and set up correctly. If your system can accept a MERV 13 filter without reducing airflow below safe operating levels, it can capture more fine particles than a basic filter. But the right filter depends on the equipment. Some older systems cannot handle a dense filter well. Check the furnace or air-handler manual, or ask a qualified HVAC technician, before changing filter ratings.
If you use central air conditioning, set the system to recirculate when that option is available. Replace a loaded filter promptly. Keep two spare filters at home during fire season, labeled with the correct size. We have seen households discover too late that their 16-by-25-by-1 filter was sold out locally because every neighbor was trying to buy one at once.
Do not use window fans to cool the house while the AQI is poor. If indoor temperatures become unsafe because you lack air conditioning, identify public clean-air spaces ahead of time, such as libraries, community centers, or shopping areas. Heat and smoke together are a different problem than smoke alone, especially for older adults.
Use masks correctly for unavoidable trips
The best smoke mask is the one that seals well enough to filter the air you breathe. A NIOSH-approved N95 respirator is the practical baseline for necessary outdoor tasks. A box of 10 to 20 N95s often costs roughly $10 to $30, depending on the brand and availability.
Cloth masks, bandanas, surgical masks, and loosely worn face coverings do not reliably filter fine smoke particles. N95s also may be hard to tolerate for people with certain medical conditions, very young children, or people who cannot achieve a seal. Do not force a respirator on someone who cannot safely wear it.
Keep respirators in their original packaging or a clean, dry container. For a household of four, storing 20 to 30 individually packaged N95s covers several smoke periods and lets adults replace damp, dirty, damaged, or poorly fitting masks. Use them for short necessary trips, not as permission to mow the lawn or exercise outdoors during unhealthy air.
Protect the household systems smoke disrupts
Wildfire smoke response is connected to more than breathing. Keep vehicle fuel above half a tank during a regional event, because driving farther for appointments, clean-air space, or a pharmacy is common. Charge phones and a battery bank. Smoke events can coincide with heat, utility strain, and short-notice evacuation orders in nearby areas.
Bring pets inside as much as possible and shorten their outdoor exercise. Keep pet medications, carriers, leashes, and food together. If school or child care remains open, decide in advance whether its air filtration and outdoor-activity policy meets your family’s needs. A child who must use a rescue inhaler more often than directed needs prompt medical attention, not a tougher attitude.
Check on one nearby older neighbor or family member. A quick call can reveal an empty inhaler, a broken air conditioner, or someone who does not know the AQI has climbed. Community preparedness often looks like sharing a spare purifier filter or offering a ride, not stockpiling more gear.
Tonight, choose the room that will serve as your clean-air room, measure its floor space, and write the correct HVAC filter size on your grocery list.