When is allergy season in Washington DC? A Guide for Every Season

Washington, DC may be famous for one very photogenic spring bloom, but cherry blossom season is only a small part of what’s happening in the air.

So, when is allergy season in Washington DC? Seasonal pollen can show up from late winter through fall. Trees typically start the season, grasses become more prominent in late spring and summer then weeds like ragweed take over later in the year. Exact timing can shift with the weather and your personal pollen triggers.

As spring unfolds, tree pollen picks up across the region. Grasses follow as temperatures rise, with weeds taking their turn by late summer. That means allergies in DC can stick around well beyond peak bloom.

Here’s how the local pollen calendar tends to unfold, what can shift it from year to year and how to stay ready when pollen picks up.

When is allergy season in Washington DC throughout the year?

Washington, DC can experience seasonal pollen from around February through October, with different pollen types dominating at different times.

Consider those ranges a seasonal heads-up, not a promise from Mother Nature. Temperature, rainfall and wind can change when pollen appears and how much becomes airborne.

Want the pollen basics first? Start with our guide to pollen season.

Which pollen shows up first in DC?

Trees generally get the season underway.

Tree pollen can begin as early as mid-to-late February in the DC area and continue into early summer, although timing varies by species and weather conditions.

Oak deserves a special mention. Historical Washington-area research found it to be a particularly significant source of tree pollen in the region.

Beautiful canopy. Busy pollen department.

When does grass pollen become a factor?

By late spring, pollen season starts changing gears.

Grass pollen typically becomes prominent around May and can continue through July. Tree pollen can still be present as grass pollen increases, so people sensitive to both may notice an overlap in late spring.

When does fall allergy season start?

Weed pollen generally becomes more prevalent from August through October, with ragweed being one of the best-known fall triggers.

Ragweed pollen is lightweight enough to travel considerable distances on the wind, so the plants immediately around you aren't necessarily the only ones that matter.

Spring may get the allergy-season spotlight, but fall has a follow-up act.

Why can DC allergy season last for months?

DC allergy season can feel lengthy because tree, grass and weed pollen arrive on different schedules and those schedules can overlap.

The region also has plenty of vegetation, from parks and lawns to tree-lined streets. Wind can carry pollen from surrounding areas too, meaning what’s airborne matters more than what’s growing directly outside your door.

Your individual trigger matters just as much.

If trees are your issue, spring may stand out. If grasses are your trigger, late spring and summer may be more noticeable. If ragweed gets you, late summer and fall deserve your attention.

How does DC weather affect pollen levels?

Temperature, wind and rain can affect when plants release pollen and how easily it moves through the air.

Warm temperatures can encourage pollen production while dry, windy conditions can help pollen travel. Rain often temporarily lowers airborne pollen by washing particles from the air.

Weather can shift the season itself, too. A colder start to the year may delay flowering while an early warm-up can bring pollen into the air sooner. That’s one reason DC’s pollen calendar can look a little different from year to year.

So while the calendar tells you what usually happens, the daily forecast tells you what your nose is actually walking into.

What should you look for in a DC pollen forecast?

Check which pollen type — tree, grass or weed — is driving the day's count, not just the overall pollen rating.

Someone sensitive to oak may pay closer attention to spring tree pollen while someone sensitive to ragweed may be more interested in late-summer weed levels.

Think of the seasonal calendar as the overview. Your daily pollen count DC forecast is the update.

What do seasonal allergies commonly feel like?

Common seasonal allergy symptoms can include sneezing, nasal congestion, a runny nose, itchy or watery eyes and sometimes coughing.

If the same issues tend to return when a particular pollen season begins, discussing those patterns with an allergist can help you understand your individual triggers.

Symptoms that hang around throughout the year may also involve indoor allergens such as dust mites, pet allergens or mold. Explore our guide to indoor allergies for more.

If symptoms are severe, unusual or persistent, talk with a healthcare professional.

What can you do when pollen is high in DC?

You can’t control what the trees are doing. Your daily routine, however, is yours.

Start with the forecast

Before an outdoor workout, afternoon on the Mall or dinner outside, check which pollen category is elevated. Comparing those levels with how you feel may also help you better understand your seasonal patterns.

Give pollen fewer ways inside

Keeping windows closed when pollen is elevated can limit what blows indoors. After spending significant time outside, showering and changing into clean clothes can also remove pollen that has settled on your hair, skin and clothing.

Basically: what happened at the park does not need to follow you onto the couch.

Add nasal cleansing to your routine

Your nasal passages interact with the air around you all day. Sinus rinsing can help cleanse mucus, pollen and other allergens from the nasal passages, making it a practical step after time outdoors.

Sinus Rinse Free + Clear is a gentle daily sinus rinse powered by Activated Saline™ with prebiotics and postbiotics to support a healthy nasal microbiome. It’s pre-mixed and ready to use for easy everyday cleansing.

For a deeper cleanse, Advanced Sinus Rinse Free + Clear is designed for deeper cleansing of mucus and allergens. It comes in single-dose rinse pouches with a reusable Nasal Pillow applicator, making it an easy option when you want to level up your rinse.

Think gentle daily cleanse vs. deeper cleanse: both are designed to cleanse mucus and allergens while helping hydrate and comfort dry, irritated nasal passages.

What does a Wizard pollen-day routine look like?

At Wizard Wellness, we like allergy care with a little less pharmacy-aisle energy.

Think simple: know what’s outside, keep more of it outside, cleanse when you come home then refresh and move on.

After extended outdoor time, a nasal rinse can help cleanse pollen and other particles from the nasal passages. Daily Nasal Spray can follow as a refreshing everyday nasal wellness step.

Wizard's proprietary Nasalbiome™ Technology puts the nasal microbiome at the center of everyday nasal wellness and is designed to support a balanced nasal microbiome.

New to the concept? Our guide to the nasal microbiome has the unstuffy science.

The goal isn't to organize your life around pollen. It's to have a routine ready when pollen organizes itself around you.

So, when is allergy season in Washington DC?

For many people, the outdoor pollen calendar runs from late winter through fall: trees first, grasses next and weeds later in the year. Your personal season depends on the pollen you're sensitive to and how conditions change each year.

Learn your triggers, check current conditions and keep your nasal wellness routine ready for whatever’s in the air.

Shop the Allergy Season Survival Ritual

Frequently asked questions

What month is pollen highest in Washington DC?

There isn't one peak month for every pollen type. Historical Washington-area research has found particularly high tree-pollen concentrations in April, while grass and weed pollen become more prominent later.

What causes spring allergies in DC?

Tree pollen is a major contributor. Oak, maple, birch, cedar, pine and hickory can all contribute to Washington, DC's spring pollen mix.

Does rain lower pollen in Washington, DC?

Rain can temporarily lower airborne pollen by washing particles from the air. However, one rainy day doesn't mean pollen season is finished.

How can I prepare for high-pollen days in DC?

Check which pollen is elevated, keep windows closed when appropriate and consider showering and changing clothes after extended outdoor time. Saline nasal rinsing can also physically cleanse pollen from the nasal cavity.