CA pollen report
San Jose Pollen Report
San Jose sits in the Santa Clara Valley, once famous as an orchard valley — and its warm, sheltered climate runs a long allergy season. Grasses pollinate across the surrounding hills from spring into fall, oak and olive trees add heavy spring loads, and the valley's enclosure lets pollen build on still, warm days.
Collection coming soon to San Jose
PollyMap is actively recruiting a verified local partner in San Jose. Be the first to know — or apply to be the partner.
While we find a local clinic
Test the air at your own home in San Jose
No allergy clinic is reporting from San Jose yet. Until one does, you can order your own PollyKit — a simple air sampler you hang outdoors or indoors. Send it back and the PollyKit Lab shows you exactly what's floating in your air.
- Pollen from local trees, grasses and weeds
- Airborne mold spores
- Dust mites and other indoor allergens
Hang it outdoors
See which pollen and mold are in your yard this season.
Or hang it indoors
Check bedrooms and living spaces for mold, dust mites and more.
What drives allergies in San Jose
Grasses: the valley's longest season (March – October)
Wild oats, ryegrass, and other annual grasses cover the Diablo and Santa Cruz ranges flanking the valley — grass is San Jose's biggest allergen season.
Trees: oak, olive, and sycamore (February – June)
Valley oak (Quercus lobata), olive, sycamore, and remnant orchard trees drive the spring season, peaking in March and April.
Weeds: ragweed and sagebrush (August – October)
Ragweed (Ambrosia) and sagebrush contribute through the fall, especially in the foothills.
Mold: mostly dry, winter exceptions
The valley's dry summers keep mold low; modest rises come with winter rains and irrigated landscaping.
Pollen patterns in San Jose
In San Jose, tree pollen — including Oak, Olive, Cypress — typically dominates from late winter through spring. Bermuda grass is the most common warm-season pollinator, and Ragweed drives the largest fall pollen load.
Top trees
- Oak
- Olive
- Cypress
- Acacia
- Sycamore
Top grasses
- Bermuda
- Rye
- Fescue
Top weeds
- Ragweed
- Sagebrush
- Pigweed
Top molds
- Cladosporium
- Alternaria
- Penicillium
San Jose pollen calendar
Typical monthly intensity across the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| tree | ||||||||||||
| grass | ||||||||||||
| weed | ||||||||||||
| mold |
Historical reports
Cities near San Jose
Explore pollen activity in nearby cities reported by the PollyMap network.
Frequently asked questions
What is the pollen count in San Jose today?
PollyMap publishes real, microscope-verified pollen counts for San Jose — measured from physical air samples. The latest report on this page shows current tree, grass, weed, and mold levels.
Is the pollen count high in San Jose right now?
San Jose's grass season runs spring through fall; trees peak in March and April. The measured reports on this page show today's actual levels.
When is allergy season in San Jose?
Trees February–June, grasses March–October, weeds in the fall — one of the longest combined seasons on the West Coast.
Why can pollen feel worse in the valley than at the coast?
The Santa Clara Valley is sheltered from ocean wind, so on still warm days pollen accumulates instead of dispersing — measured local counts tell the real story.
Is pollen still bad in San Jose in the fall?
Yes, modestly. The South Bay's mild fall keeps grass pollen lingering, and mold spores rise with the first seasonal rains. San Jose's Mediterranean climate means pollen season never fully stops.
Are you an allergy clinic in San Jose? Claim your territory on PollyMap.
PollyMap is a local authority-building tool for allergy clinics, ENT practices, and any clinic that offers allergy care. By becoming the Official PollyMap Partner for your part of San Jose, your clinic gets credited on real pollen reports, receives ready-to-share weekly content, and becomes the go-to local expert patients trust.
We assign each partner a designated territory within the San Jose metro — like a franchise territory. San Jose has room for multiple partners, but once your area is assigned, it's locked to your clinic.
No clinic has claimed a territory in San Jose yet. The best areas go to the first clinics that sign up — once one does, that part of town is off the table for everyone else.
Silicon Valley is a string of territories — San Jose, Sunnyvale, Santa Clara, Mountain View, and Cupertino each qualify. First clinic in each area becomes its credited pollen expert.
- Your clinic credited on every San Jose pollen report
- Weekly real-sample reports and ready-to-share content under your brand
- Locked territory — competing clinics can't claim your area
- Become the go-to allergy expert in your part of San Jose
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