Whatcom County is under both a heat advisory and an air quality alert through Wednesday evening, July 22, as a combination of Canadian wildfire smoke and rising temperatures creates health risks for residents across the region. Officials from Whatcom County Health and Community Services are urging people to take precautions, particularly those in vulnerable groups.
The Northwest Clean Air Agency issued the air quality alert for Whatcom and Skagit counties, effective through 9 a.m. Wednesday, July 22. The heat advisory, issued by the National Weather Service, runs from 10 a.m. Tuesday, July 21 through 11 p.m. Wednesday. Temperatures are expected to approach 90 degrees Fahrenheit in parts of the county, with Bellingham seeing mid-80s and locations further north such as Lynden and Sumas likely warmer.
Smoke Conditions and Who Is Most at Risk
Wildfire smoke from the Brunswick Complex fires in British Columbia, which have burned more than 50,000 acres on both sides of the Trans-Canada Highway, is drifting south into Whatcom County. Additional smoke is arriving from fires burning east of the Cascades, including the Ptarmigan Fire near the North Cascades. The smoke is expected to keep particulate matter, specifically PM2.5 fine particles, at levels that are unhealthy for sensitive groups.
Those most at risk include children, older adults age 65 and above, pregnant individuals, and people with heart or lung conditions such as asthma or COPD. For these groups, even brief outdoor exposure during elevated smoke periods can trigger respiratory symptoms and cardiovascular stress. Health officials note that cloth masks do not protect against wildfire smoke particles; only a well-fitting N95 mask provides meaningful filtration when someone must be outside in smoky air.
Wildfire smoke contains fine particles that irritate the eyes, nose, throat, and lungs. At current forecast levels, even people without underlying health conditions should watch for symptoms such as coughing, shortness of breath, or eye irritation as a signal to reduce outdoor exposure.
Staying Cool and Keeping Indoor Air Clean
Whatcom County Health and Community Services recommends a layered approach to managing both the heat and the smoke simultaneously. The challenge is that opening windows and doors to cool a home also lets smoke in, while keeping windows closed traps heat. The county's guidance addresses that tension directly.
If you have air conditioning, set it to recirculate indoor air rather than drawing in outside air. A portable HEPA air purifier provides additional protection. A low-cost alternative recommended by health officials is a DIY filter: tape a furnace filter to the back of a standard box fan to capture particulates. Avoid activities that add particles to indoor air, including smoking, burning candles, vacuuming, and frying or broiling food.
For residents without air conditioning, the county advises visiting cooled public spaces such as libraries, shopping centers, or movie theaters during peak afternoon heat. Bellingham Public Library branches offer air-conditioned space for as long as residents need. Fans alone are not sufficient when indoor temperatures exceed 90 degrees, which can occur in south-facing or poorly insulated homes even on days when outdoor temperatures are only in the mid-80s.
Hydration is essential during any heat event. Drink water steadily throughout the day and avoid sugary, caffeinated, or alcoholic beverages, which accelerate dehydration. Close window coverings on the sun-facing sides of your home during the hottest hours to keep interior temperatures down.
Water Safety and Checking on Neighbors
The county is also reminding residents that heading to a lake or the bay to cool off carries its own risks. Water temperatures in local lakes and Bellingham Bay remain dangerously cold in July despite the warm air temperatures, and "cold shock" from sudden immersion can cause involuntary gasping, rapid breathing, and loss of muscle control within minutes. This is a serious drowning risk even for strong swimmers. Life jackets are essential for any time on the water.
Health officials are asking residents to check on neighbors who are older adults, live alone, or lack access to air conditioning. A brief visit or phone call during a heat event can identify people who need help accessing cooling resources before a medical emergency develops.
Never leave children or pets in a parked vehicle. Even with windows cracked, interior car temperatures can exceed 100 degrees within minutes on an 85-degree day.
For current air quality readings updated throughout the day, residents can use the AirNow app or the Northwest Clean Air Agency website. Smoke forecasts are also available from the Washington State Smoke Blog. The Whatcom County Health and Community Services wildfire smoke and extreme heat pages have additional guidance. For earlier coverage on Whatcom County fire conditions and burn bans, more background is available in this report on county public safety conditions.
