Austin · Indoor air
Cedar fever season and your home's air
February 2026 · 4 min read
Mountain cedar pollen counts in Central Texas can run into the tens of thousands of grains per cubic meter, which is among the highest of any allergen in the country. Your house either filters that or circulates it.
The filter is the front line
During cedar season, filter changes matter more than at any other time of the year, and a loose filter slot undoes the whole thing.
- Change filters monthly from December through February.
- Use MERV 11 if the system tolerates it, but watch for restricted airflow.
- Seal gaps around the filter rack so air cannot bypass the media.
- Replace warped or crushed filters immediately, since they let air past the edge.
Where pollen gets in
Filtration only works on air that goes through the system. Everything else is infiltration.
- Leaky return ducts in the attic pull in dusty, pollen-laden air.
- Failed weatherstripping at exterior doors, especially the garage door into the house.
- Unsealed attic hatches and can lights.
- Window screens and sills that never get rinsed off in January.
Worth doing once
Sealing return-side duct joints and mastic-taping the plenum is a one-time job that pays back every allergy season, and it usually improves cooling performance as a bonus.
Questions we get
- When is cedar season in Austin?
- Mountain cedar pollinates from roughly mid-December through February, peaking in January. It is the most intense allergy period of the Central Texas year.
- Do air purifiers help with cedar fever?
- Room HEPA units help in bedrooms and offices. Whole-home results come from good filtration in the HVAC system plus reducing the air leaking in from the attic.
- Should I get my ducts cleaned?
- Duct cleaning is oversold. Sealing leaks and fixing filtration usually delivers more, though cleaning makes sense after renovation dust or if there is visible contamination.
Rather not track all this?
Well Kept Home members get this work scheduled through the year by the same Austin crew, with written notes and photos after every visit.