Austin's Year-Round Pollen Calendar
Austin doesn't really have an allergy off-season. Cedar fever dominates December through February, but the moment cedar winds down, the spring pollen parade begins. Oak trees, and Austin has millions of them, start releasing pollen in late February and peak through April. Elm, ash, and pecan follow. By May and June, grass pollen takes over.
For the roughly 30–40% of Austin residents who suffer from seasonal allergies, this means nearly six months of elevated pollen exposure. Understanding which allergens peak when, and how to configure your HVAC accordingly, makes a real difference.
The Austin Spring Pollen Calendar
| Month | Primary Allergens | Typical Pollen Count |
|---|---|---|
| February | Mountain cedar (winding down), elm | High |
| March | Oak, elm, ash | Very High |
| April | Oak (peak), pecan | Very High |
| May | Oak (declining), grass begins | High |
| June | Grass, ragweed begins | Moderate–High |
Oak pollen is particularly problematic because the particles are smaller than cedar, typically 15–25 microns, and the trees produce enormous quantities. A single large live oak can release billions of pollen grains per day during peak season.
How Your HVAC Can Help (and Hurt)
Your air conditioning system is running almost constantly during Austin's spring and summer. That's both an opportunity and a risk. Every time it cycles on, it draws air through your filter, which is good if the filter is doing its job. But if your filter is undersized, clogged, or the wrong MERV rating, your system is actively distributing pollen throughout your home.
The key upgrades for spring pollen season:
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MERV 11–13 pleated filter. The same recommendation as cedar season. Oak and grass pollen particles are well within the capture range of a quality pleated filter. Replace every 30–45 days during peak season.
Keep the fresh-air damper closed during high-pollen days. Many Austin homes have a fresh-air intake damper on the HVAC system. During peak pollen days (check AirNow.gov or the Weather Channel app for Austin pollen forecasts), close this damper to prevent drawing in outdoor air. Reopen it on low-pollen days to ventilate.
Run the fan continuously. Set your thermostat fan to "ON" rather than "AUTO" during high-pollen periods. This keeps air cycling through the filter even when the system isn't actively cooling.
Whole-Home Air Purifiers for Spring Pollen
A MERV filter captures pollen at the filter. A whole-home air purifier like the REME HALO goes further, it actively treats the air throughout your entire home, neutralizing allergens that are already circulating. The REME HALO uses photohydroionization technology to create hydrogen peroxide molecules that seek out and neutralize airborne particles, including pollen, mold spores, and bacteria.
For Austin homeowners with moderate to severe spring allergies, the combination of a quality filter and a REME HALO is the most effective approach available short of a medical-grade air filtration system. Most homeowners notice a meaningful reduction in indoor allergy symptoms within the first few days.
Don't Forget the Coils
Your AC's evaporator coil is a prime location for mold and bacteria growth, especially in Austin's humid spring climate. A dirty coil also reduces your system's ability to dehumidify, which worsens allergy symptoms. A UV-C light installed near the coil keeps it clean and prevents microbial growth, which is a separate but complementary benefit to pollen filtration.
Practical Tips for Peak Pollen Days
Beyond your HVAC, a few habits make a big difference during peak spring pollen weeks in Austin: shower and change clothes when coming indoors, keep windows closed from 5 a.m. to noon when pollen counts are highest, and vacuum with a HEPA-filter vacuum at least twice a week. Your HVAC handles the air; these habits handle the pollen you track in on your clothes and shoes.
For more on specific products, see our breakdown of the REME HALO air purifier [blocked] and our MERV filter guide [blocked]. If cedar season is your bigger issue, start with our cedar fever HVAC guide [blocked].
