CO pollen report
Denver Pollen Report
Denver's high, dry climate doesn't mean allergy relief — the Front Range runs a full calendar. Elm and juniper start in early spring, cottonwoods fill the air with pollen (and fluff) in late spring, prairie grasses carry the summer, and ragweed and sagebrush close out the fall. Chinook winds and dry air keep pollen aloft and traveling across the metro.
Collection coming soon to Denver
PollyMap is actively recruiting a verified local partner in Denver. Be the first to know — or apply to be the partner.
While we find a local clinic
Test the air at your own home in Denver
No allergy clinic is reporting from Denver yet. Until one does, you can order your own PollyKit — a simple air sampler you hang outdoors or indoors. Send it back and the PollyKit Lab shows you exactly what's floating in your air.
- Pollen from local trees, grasses and weeds
- Airborne mold spores
- Dust mites and other indoor allergens
Hang it outdoors
See which pollen and mold are in your yard this season.
Or hang it indoors
Check bedrooms and living spaces for mold, dust mites and more.
What drives allergies in Denver
Trees: elm, juniper, and cottonwood (March – June)
Siberian elm and Rocky Mountain juniper start the season in March; plains cottonwood (Populus deltoides) peaks in May along the South Platte corridor.
Grasses: Kentucky bluegrass and prairie grasses (May – August)
Bluegrass lawns and native prairie grasses pollinate heavily in June — Denver's peak grass month.
Weeds: ragweed and sagebrush (August – October)
Ragweed (Ambrosia) and sagebrush (Artemisia) dominate the fall, with Russian thistle adding to windy-day counts.
Mold: low but storm-linked
Outdoor mold is modest in the dry climate but spikes after summer thunderstorms and during irrigated lawn season.
Pollen patterns in Denver
In Denver, tree pollen — including Juniper, Cedar, Cottonwood — typically dominates from late winter through spring. Brome grass is the most common warm-season pollinator, and Sagebrush drives the largest fall pollen load.
Top trees
- Juniper
- Cedar
- Cottonwood
- Pine
- Aspen
Top grasses
- Brome
- Bluegrass
- Fescue
Top weeds
- Sagebrush
- Ragweed
- Russian thistle
Top molds
- Cladosporium
- Alternaria
Denver pollen calendar
Typical monthly intensity across the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| tree | ||||||||||||
| grass | ||||||||||||
| weed | ||||||||||||
| mold |
Historical reports
Cities near Denver
Explore pollen activity in nearby cities reported by the PollyMap network.
Frequently asked questions
What is the pollen count in Denver today?
PollyMap publishes real, microscope-verified pollen counts for Denver — measured from physical air samples. The latest report on this page shows current tree, grass, weed, and mold levels.
Is the pollen count high in Denver right now?
Denver's worst stretches are April–May (elm, cottonwood) and June (grasses), with ragweed in September. The measured reports on this page show today's actual levels.
When is allergy season in Denver?
March through October: trees in spring, grasses in early summer, and ragweed and sagebrush in the fall. Winter is the only real break.
Does the dry climate help allergies in Denver?
Only partly. Dry air means less mold, but it also keeps pollen airborne longer, and Front Range winds spread it for miles. Irrigated lawns and river corridors add plenty of pollen sources.
Are you an allergy clinic in Denver? Claim your territory on PollyMap.
PollyMap is a local authority-building tool for allergy clinics, ENT practices, and any clinic that offers allergy care. By becoming the Official PollyMap Partner for your part of Denver, your clinic gets credited on real pollen reports, receives ready-to-share weekly content, and becomes the go-to local expert patients trust.
We assign each partner a designated territory within the Denver metro — like a franchise territory. Denver has room for multiple partners, but once your area is assigned, it's locked to your clinic.
No clinic has claimed a territory in Denver yet. The best areas go to the first clinics that sign up — once one does, that part of town is off the table for everyone else.
The Front Range is one long opportunity — Denver, Aurora, Boulder, Littleton, and Fort Collins can each support PollyMap territories. First clinic in each area becomes its credited pollen expert.
- Your clinic credited on every Denver pollen report
- Weekly real-sample reports and ready-to-share content under your brand
- Locked territory — competing clinics can't claim your area
- Become the go-to allergy expert in your part of Denver
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