Pollen Level
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Gathering pollen, air quality, and weather data for you.
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Pollen Level
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Gathering pollen, air quality, and weather data for you.
Gathering pollen, air quality, and weather data for you.
Pollen Level
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Air Quality
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Longmont's allergy season is relatively mild compared to other US regions, running from April through September. However, the dry air and altitude around Longmont, CO create unique challenges — pollen travels further and dry conditions can irritate airways.
Right now: May brings increasing tree pollen to Longmont. Pine pollen is visible but usually less allergenic than it looks.
Spring
Apr – Jun
Juniper, pine, and cottonwood tree pollen peak at lower elevations.
Summer
Jun – Aug
Grass pollen peaks. Higher elevations see delayed and shorter seasons.
Fall
Aug – Sep
Sagebrush and ragweed in lower elevations. Season ends earlier at altitude.
Dry air near Longmont can carry pollen over longer distances, but lower humidity means less mold than in humid regions. Elevation significantly affects local pollen timing — even a 30-minute drive changes conditions. PollenTracker accounts for these variations.
Open another nearby forecast without going back to the map.
CAUTION
Grass pollen is high (250 grains/m³) and air quality is fair. Plan outdoor time for the safest hours below.
Pollen: Grass pollen is high today at 250 grains/m³.
Lower-risk hours: 11:00, 17:00-18:00
Weather
57°F
Overcast · 73% humidity · 5 mph wind
~5 grains/m³