Pollen Today for Longmont, CO
Great
Low pollen in Longmont, CO today
Tree: Low · Grass: Low · Weed: Low
Low
a good day for allergy sufferers
Tree pollenLow (UPI 0/5)
UPI is the Universal Pollen Index, a 0–5 scale (0 none, 5 very high) that is comparable across pollen types and locations.
- Grass pollenLow (UPI 0/5)
- Weed pollenLow (UPI 0/5)
- TimingCounts peak 10am–3pm; lowest overnight and after rain
- TipGood day for outdoor activities
Data as of Jul 21, 2026
Coming Up
MonLowGreat
TueLowGreat
WedLowGreat
ThuLowGreat
FriLowGreat
Pollen season outlook for Longmont
The pollen model for Longmont shows no plant species actively releasing pollen right now — a break for allergy sufferers.
Grass pollen is the usual suspect this time of year, typically peaking from May through July.
Across most of the US the pollen year follows the same arc: trees lead from roughly March through May, grasses take over from May through July, and weeds — led by ragweed — dominate August until the first frost. The seasons overlap, and in warm climates something is usually in the air nearly year-round.