Colorado, United States

Fort Collins, CO Pollen Count Today

View the current allergy index, primary allergen, tree, grass, and weed pollen levels, plus the 5-day pollen forecast for Fort Collins.

Today's pollen count in Fort Collins

Today in Fort Collins, Colorado, the forecasted pollen level is very high with an allergy index of 5. The primary allergen is Birch. Use the forecast below to see whether conditions are likely to rise, ease, or stay steady over the next few days.

AllergyAva shows forecasted pollen levels and allergy risk estimates for Fort Collins. Actual exposure can vary by neighborhood, weather, and time outdoors.

Current level
Very High
Allergy index
5
Main allergen
Birch

Pollen Level

Very High Risk
5

Pollen Index

Primary Allergen

Birch

Stay indoors when possible. Use HEPA filters and take prescribed medication.

80°

Temp

74%

Humidity

13

Wind mph

Source: Includes pollen data from Google

Updated May 13, 2026 at 6:27 PM ET.

Check pollen in another city or ZIP code

5-Day Pollen Forecast

Best day this week

Sat - None

Worst day this week

Tomorrow - Very High

Today
68°/64°
1
Very Low
Tree4
Grass0
Weed0
Tomorrow
72°/48°
5
Very High
Tree3
Grass0
Weed0
Fri
70°/53°
2
Low
Tree2
Grass0
Weed0
Sat
81°/47°
0
None
Tree4
Grass0
Weed0
Sun
88°/56°
3
Moderate
Tree3
Grass0
Weed0
None
Very Low
Low
Moderate
High
Very High

Allergen Breakdown

Birch
Very High
Oak
Moderate
Cedar
Moderate
Maple
Low

Pollen & Allergy Guide for Fort Collins, CO

Fort Collins, Colorado residents can experience significant pollen exposure throughout the year. Tree pollen typically peaks during spring months, while grass pollen dominates in summer. Fall brings elevated ragweed levels, which is one of the most common allergens in the region.

When Is Allergy Season in Fort Collins?

Allergy season in Fort Collins generally begins in early spring as trees start releasing pollen. The most intense period varies by allergen type. Monitoring daily pollen counts with Allergy Ava helps you plan ahead and manage symptoms proactively.

Tips for Managing Allergies in Fort Collins

Track your daily pollen exposure, consult with a local allergist for personalized treatment, and consider starting preventive medications 2-4 weeks before your peak allergy season. Indoor air quality management with HEPA filters can also make a significant difference.

Fort Collins allergy season calendar

Tree pollen

In season now

Spring

Often drives early-season symptoms

Grass pollen

In season now

Late spring to summer

Can rise around lawns, parks, and open areas

Ragweed/weed pollen

Late summer to fall

Major fall allergy trigger

Mold spores

Varies

Often affected by moisture and decaying leaves

Common pollen triggers around Fort Collins

TriggerTypical seasonWhat to know
Tree pollenSpringOften drives early-season symptoms
Grass pollenLate spring to summerCan rise around lawns, parks, and open areas
Ragweed/weed pollenLate summer to fallMajor fall allergy trigger
Mold sporesVariesOften affected by moisture and decaying leaves

Frequently asked questions about pollen in Fort Collins

What is the pollen count in Fort Collins today?

Today in Fort Collins, Colorado, the pollen level is very high with an allergy index of 5. The main allergen to watch is Birch.

When is allergy season in Fort Collins, Colorado?

Allergy season in Fort Collins, Colorado can vary by allergen and weather conditions. Tree pollen often rises in spring, grass pollen becomes more active in late spring and summer, and weed pollen can remain elevated later in the year depending on local climate and vegetation.

How often should I check the pollen forecast in Fort Collins?

If you have seasonal allergies in Fort Collins, it is helpful to check the pollen forecast daily during peak allergy periods. Shifts in wind, rainfall, temperature, and humidity can all change local pollen exposure from one day to the next.

What pollen types affect people in Fort Collins, Colorado?

Fort Collins residents may be affected by tree pollen, grass pollen, and weed pollen during different parts of the year. The strongest trigger depends on the season, nearby vegetation, and current weather conditions.