Tree Pollen Count in Longmont, CO — Today

Updated Sunday, November 8, 2026

Pollen by type in Longmont

What is the tree pollen count in Longmont today?

The Longmont tree pollen index today is 0.6 (Low) on Pollen Atlas’s modelled 0–100 scale. Low

Modelled pollen risk index — not a measured count.

Longmont’s overall pollen count today is 25 (Low) across all types. See the full Longmont pollen count for the overall index and every type together.

Longmont is a city spanning Boulder County and Weld County in Colorado. Its population is 98,958 (ACS 2023).

Longmont Tree Pollen Count: 5-Day Forecast

DayOverall indexCategory
Sunday, November 825Low
Monday, November 922Low
Tuesday, November 1024Low
Wednesday, November 1124Low
Thursday, November 1221Low

Pollen Atlas models the daily detail as an overall index: day-by-day splits by individual pollen type are not part of the modelled data, so this table shows Longmont’s overall trend across the week. Today’s tree pollen reading is the headline above.

Species driving Longmont’s tree pollen

Species-level counts are not part of the modelled data Pollen Atlas publishes — the modelled index is reported per pollen type, not per species — so this section gives the type summary: tree pollen reads 0.6 (Low) today. The plant-by-plant detail that is available, from the Google Pollen API, is in the next section.

Plants affecting Longmont now — tree pollen

Detailed plant-by-plant readings for the tree pollen category were not returned in today’s source data for Longmont. The type summary stands: tree pollen reads 0.6 (Low) today.

In the Mountain West pattern, the plants that typically shape this city’s year are spring trees and late-spring grasses in a compressed warm-season window — named here as regional context only, not as today’s readings.

Plant detail returns here automatically on any day the feed includes it.

What this tree pollen level means

Low risk. Keep windows open; consider allergy meds only if sensitive.

Enjoy outdoor activities.

Juniper can arrive in late winter, and the main tree wave builds in spring — as late as April at Denver’s altitude. This month sits outside the usual tree pollen window for the Mountain West pattern, so today’s tree pollen reading is the modelled value outranking the calendar — this page reports the modelled reading first. The Colorado allergy season guide singles out juniper, arriving ahead of the local tree season, and the ragweed and sagebrush-family weeds of late summer.

Longmont allergies today

Longmont allergies today are set by the same reading as the Longmont pollen count today: the Total Pollen Index is 25 (Low), and the tree pollen index on this page is 0.6 (Low) of it. When people ask about Longmont allergies, this is the number that answers them — one daily modelled index built from today’s tree, grass and weed index values for Longmont.

Allergies in Longmont follow the Colorado calendar set out on the full Longmont page — the chapters, the plants behind them, and the 5-day forecast show whether today is typical for the season or an exception to it. If you are checking allergies today in Longmont before heading outdoors, the tree pollen split on this page is the part to read: it shows whether this pollen type is doing the work today, not just how high the total sits.

Read the five-day overall trend above as the Longmont allergy forecast for the tree pollen season: it shows whether Longmont allergies are set to ease or build across the week, day by day — the days to plan outdoor time around are the ones where the overall index steps down, not just today.

See the full Longmont pollen count — all types, the overall index and today’s ranking context

Longmont grass pollen count

Longmont ragweed pollen count

See how Longmont ranks in today's pollen count rankings — the worst cities for allergies today

See Longmont on the pollen map

Every pollen type, with photos and seasons: the pollen directory

Colorado allergy season guide

Tree pollen season

Find an allergist in Longmont, CO

Pollen indexes: a modelled pollen risk index computed by Pollen Atlas from open weather, vegetation and phenology data, calibrated against CDC/NAB season data. Plant detail: Google Pollen API. Index values are modelled, not measured counts. Sources: CDC/NAB; USA-NPN; GBIF (CC BY); ESA WorldCover (CC BY 4.0).