MT · Allergy Season Guide
Montana Allergy Season Guide
Montana experiences a high-elevation semi-arid to alpine climate with cold winters, warm dry summers, and dramatic day-night temperature swings.
Summary
Montana has 0 active PollyMap collection sites, and is seeking partners in 5 additional cities. Tree pollen typically dominates early spring, grass pollen peaks in late spring and early summer, and weed pollen (including ragweed) extends from late summer through fall.
PollyMap collection status across Montana
While we find a local clinic
Test the air at your own home in Montana
No allergy clinic is reporting from Montana 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.
Statewide allergy overview
Montana experiences a high-elevation semi-arid to alpine climate with cold winters, warm dry summers, and dramatic day-night temperature swings.
Juniper, cedar, and cottonwood drive an early-spring tree season. Grasses peak in early summer and sagebrush is the dominant fall weed.
Mold counts are typically lower at altitude but spike after monsoon storms and irrigated agricultural cycles in the lower valleys.
Allergy patterns vary by elevation and proximity to coast or mountains within Montana, but most of the state shares a common seasonal rhythm of spring tree pollen, summer grass pollen, and late-summer to fall weed pollen.
Montana allergy calendar
Month-by-month intensity for the four major airborne allergen categories.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tree | Low | Mod | High | V.High | V.High | High | Mod | Low | Low | Low | Low | Low |
| Grass | — | — | Low | Mod | High | V.High | High | Mod | Low | Low | — | — |
| Weed | Low | Low | Low | Mod | Mod | Mod | High | V.High | V.High | High | Mod | Low |
| Mold | Low | Low | Mod | Mod | Mod | Mod | High | High | Mod | Mod | Low | Low |
Top tree pollens
Top weed pollens
Top airborne molds
Major city guides in Montana
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Billings
View Billings allergy season guide →
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Missoula
View Missoula allergy season guide →
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Great Falls
View Great Falls allergy season guide →
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Bozeman
View Bozeman allergy season guide →
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Helena
View Helena allergy season guide →
Latest PollyMap reports for Montana
Frequently asked questions
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