Simi Valley pollen forecast - today, tomorrow and the week ahead
Today (9 August) pollen in Simi Valley is medium; mugwort and ragweed are medium; cypress and grass are low. Tomorrow (10 August 2026) levels are similar - grass remains low, ragweed remains medium, mugwort declining. Over the following five days cypress, grass, mugwort, and ragweed will increase. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.
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Simi Valley's parks, including Rancho Santa Susana Community Park and the Arroyo Simi corridor, feature oak, sycamore, and introduced eucalyptus as the main tree pollen sources, with exposure varying between these green areas and the more built-up city centre. Surrounding Ventura County chaparral and the Santa Susana Mountain foothills contribute substantial grass and scrub pollen under prevailing offshore winds.
Today - 9 August
-
Alder (Alnus):
None
0/100
-
Birch (Betula):
None
0/100
-
Hazel (Corylus):
None
0/100
-
Cypress (Cupressaceae):
Low
4/100
-
Grass (Poaceae):
Low
8/100
-
Willow (Salicaceae):
None
0/100
-
Mugwort (Artemisia):
Medium
33/100
-
Ragweed (Ambrosia):
Medium
34/100
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 - 10 August
-
Alder (Alnus):
None
0/100
-
Birch (Betula):
None
0/100
-
Hazel (Corylus):
None
0/100
-
Cypress (Cupressaceae):
None
0/100
-
Grass (Poaceae):
Low
1/100
-
Willow (Salicaceae):
None
0/100
-
Mugwort (Artemisia):
Low
24/100
-
Ragweed (Ambrosia):
Medium
27/100
Air quality in Simi Valley
View air qualityPollen forecast for neighborhoods and landmarks in Simi Valley
Sports venues in Simi Valley
Frequently Asked Questions
Is pollen high in Simi Valley right now?
On 9 August 2026, overall pollen levels in Simi Valley are moderate. Ambrosia is the main contributor to airborne pollen, while artemisia, cypress, and grass remain at lower levels
Will pollen levels change in Simi Valley tomorrow?
On 10 August 2026, pollen conditions in Simi Valley will be different from today, with grass at low levels, ambrosia at medium levels and artemisia continuing to decline
Is pollen expected to decrease in Simi Valley this week?
According to the five-day outlook, cypress, grass, ambrosia, and artemisia pollen levels will increase later in the week.
Which pollen types are currently active in Simi Valley?
On 9 August 2026, Ambrosia is the dominant pollen source in Simi Valley. artemisia, cypress, and grass are also present but at lower levels.
When is pollen season in Simi Valley?
How often is the Simi Valley pollen forecast updated?
The Simi Valley pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Simi Valley 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 Simi Valley 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 Simi Valley, 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: 10 August 2026 at 02:34 CEST (Data is updated four times daily.)
This page provides the latest public pollen forecast for Simi Valley.
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Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.