Question 1

What are the three pollen types?

Accepted Answer

Tree pollen comes from species like birch, alder, oak, and olive — typically peaking in spring (March–May). Grass pollen comes from lawn grasses, timothy, and ryegrass — peaking in late spring and early summer (May–July). Weed pollen comes from ragweed, mugwort, and plantain — peaking in late summer and fall (August–October). If you know which type you're allergic to, watch that row specifically.

Question 2

What is the action level for pollen?

Accepted Answer

We report pollen on the Universal Pollen Index (UPI), a 0–5 scale: 0 is none, 1 very low, 2 low, 3 moderate, 4 high, and 5 very high. We group these into four levels — low (UPI 0–2), moderate (3), high (4), and very high (5). At moderate and above, sensitive individuals usually start to notice symptoms; at high and very high, most allergy sufferers are affected. The index already accounts for the relative potency of each allergen type, so a 4 in grass and a 4 in tree pollen represent comparable symptom risk.

Question 3

When is pollen worst during the day?

Accepted Answer

Pollen counts are typically highest in the late morning and early afternoon (10am–3pm) as temperatures rise and flowers open. Counts drop in the late afternoon and evening, and are lowest overnight. Rain temporarily washes pollen from the air, but levels often spike sharply the following morning.

Question 4

How can I reduce pollen exposure?

Accepted Answer

Check the forecast before planning outdoor activities. On high-pollen days: keep windows closed, run the AC instead, shower and change clothes after being outdoors, wear wraparound sunglasses outside, and avoid line-drying laundry. HEPA air purifiers effectively filter pollen indoors — look for a CADR rating appropriate for your room size.

Question 5

Do air purifiers actually help with pollen?

Accepted Answer

Yes — HEPA filters capture particles down to 0.3 microns, and pollen grains are typically 10–100 microns, well within that range. A true HEPA purifier (not just a 'HEPA-type' filter) will significantly reduce indoor pollen. Size the unit for your room: look for a CADR (Clean Air Delivery Rate) of at least 2/3 of the room's square footage.

Question 6

What is the difference between allergy and cold symptoms?

Accepted Answer

Key differences: allergies cause itchy eyes, nose, and throat; colds rarely do. Allergy symptoms start immediately after exposure; cold symptoms develop over 1–3 days. Allergies never cause fever; colds often do. Allergy symptoms persist as long as you're exposed to the trigger; colds resolve in 7–10 days. Watery, clear discharge suggests allergies; thick yellow/green discharge suggests infection.

Question 7

Can pollen allergies develop in adulthood?

Accepted Answer

Yes — allergies can develop at any age, even if you've lived in the same area for years. Repeated low-level exposure can sensitize the immune system over time. Moving to a new region can trigger new allergies as your body encounters novel pollen types. Adults who develop new allergy symptoms should see an allergist for testing to identify the specific triggers.

Question 8

When does pollen season end?

Accepted Answer

It depends on which pollen affects you. Tree pollen usually winds down by late May, grass pollen by mid-to-late July, and weed pollen — the last act of the year — continues until the first hard frost, typically October or November. In warm southern climates the seasons blur together and low-level pollen can persist nearly year-round; in Texas and the Southwest, mountain cedar even pollinates in the middle of winter. The 5-day forecast above shows where your area is in the current season.

Question 9

Why is the pollen count high today?

Accepted Answer

High counts usually mean a local species is in peak bloom and the weather is cooperating with it: warm, dry, breezy days carry the most pollen, and counts often spike the morning after rain as plants release what the shower interrupted. Wind can also transport pollen many miles, so counts can be high even if nothing near you looks like it's blooming. Check the species list above to see exactly what's driving today's number.

Question 10

Are allergy shots worth it?

Accepted Answer

Allergy immunotherapy (shots or sublingual drops) is the only treatment that addresses the underlying cause rather than symptoms. A typical shot regimen takes 3–5 years and can provide long-lasting relief after completion. It's most effective for people with moderate to severe symptoms that aren't controlled well by antihistamines. Discuss with an allergist — they can test which specific pollens you're reactive to and build a customized serum.

Low pollen in Boulder, CO today

Coming Up

What’s in the air in Boulder right now

FAQ

Nearby Cities