Longmont pollen forecast - today, tomorrow and the week ahead
Today (25 June) pollen in Longmont is low; grass is low. Tomorrow (26 June 2026) levels are similar - grass increasing, willow at low levels. Over the following five days grass and willow will decrease. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.
For long term forecasts and maps, see the Airmine app
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
Longmont's parks, including Sandstone Ranch and the St. Vrain Creek corridor, feature cottonwood, ash, and oak as the main tree pollen sources, with exposure varying between these green areas and the more built-up city centre. Surrounding Colorado farmland and the open plains to the east contribute substantial grass pollen, while the Front Range setting channels prevailing westerly winds and can concentrate pollen across the city.
Today - 25 June
-
Alder (Alnus):
None
0/100
-
Birch (Betula):
None
0/100
-
Hazel (Corylus):
None
0/100
-
Cypress (Cupressaceae):
None
0/100
-
Grass (Poaceae):
Low
22/100
-
Willow (Salicaceae):
None
0/100
High pollen levels may trigger sneezing, itchy eyes, and congestion. Airmine's neighbourhood estimates use satellites to map local vegetation and a statistical prediction model, updated four times daily.
Tomorrow - 26 June
-
Alder (Alnus):
None
0/100
-
Birch (Betula):
None
0/100
-
Hazel (Corylus):
None
0/100
-
Cypress (Cupressaceae):
None
0/100
-
Grass (Poaceae):
High
54/100
-
Willow (Salicaceae):
Low
22/100
Frequently Asked Questions
Is pollen high in Longmont right now?
On 25 June 2026, overall pollen levels in Longmont are low. Grass is the main contributor to airborne pollen
Will pollen levels change in Longmont tomorrow?
On 26 June 2026, pollen conditions in Longmont will be different from today, with willow at low levels and grass increasing
Is pollen expected to decrease in Longmont this week?
According to the five-day outlook, willow and grass pollen levels are expected to gradually decrease, suggesting improving conditions later in the week.
Which pollen types are currently active in Longmont?
On 25 June 2026, Grass is the dominant pollen source in Longmont. willow, hazel, and cypress are not currently active.
When is pollen season in Longmont?
How often is the Longmont pollen forecast updated?
The Longmont pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Longmont come from nearby or far away?
Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.
Are pollen levels in Longmont based on measurements or forecasts?
Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.
Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in Longmont, modern forecasts combine recent measurements, weather data, and information about local vegetation.
This allows us to estimate pollen levels for today and the coming days, not just report the past.
Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.
Want to see pollen forecasts for other cities in United States?
Check pollen in other popular cities:
Data provided by Airmine — Last update: 25 Jun 2026, 09:00 CET (Data is updated four times daily.)
This page provides the latest public pollen forecast for Longmont.
For long term forecasts and maps, see the Airmine app
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.