Very High Pollen in Ontario, CA

About pollen in Ontario

Tree pollen is dominating in Ontario today, reaching a very high level that is likely to cause significant symptoms for anyone sensitive to it. Oak, ash, pine, plane, and Schinus trees are the main contributors this season, and at this level, those prone to allergies should expect noticeable irritation. Grass and weed pollen remain minor factors right now, with grass especially quiet and weeds only mildly present. Looking ahead, grass and weed levels are expected to stay low through the next several days, offering little additional concern on that front. Tree pollen data for the coming days isn't detailed beyond today, but given the current intensity, it would be wise to stay prepared for continued high output in the near term. While autumn is typically associated with weed pollen like ragweed rather than tree activity, warm-climate regions such as Ontario can see certain trees, including Schinus and pine, release pollen outside the typical spring peak, which explains today's unusually strong tree reading.

What to do today

• Pollen is very high today; stay indoors when you can, especially midday and afternoon.
• Keep windows closed and run air on recirculate.
• Shower and change clothes right after coming inside.
• Consider allergy medication, and see a clinician if symptoms are severe.

Tree map

Every dot is a tree near Ontario, colored by how allergenic it is. Click one for its details, and zoom in for a closer look.

Top tree-pollen sources

The local tree genera behind today's pollen near Ontario. Each bar is that genus's share of the tree pollen.

Meet the trees near you

Get to know the tree types growing around Ontario: what each looks like, how allergenic it is, and when it blooms.

American sweetgum

Liquidambar styraciflua

Allergenicity 2/4Blooms spring

Ornamental pear

Pyrus calleryana

Allergenicity 1/4Blooms spring

Silver maple

Acer saccharinum

Allergenicity 3/4Blooms spring

Tulip tree

Liriodendron tulipifera

Allergenicity 1/4Blooms spring

Chinese elm

Ulmus parvifolia

Allergenicity 3/4Blooms spring

Canary island pine

Pinus canariensis

Allergenicity 1/4Blooms spring

Aleppo pine

Pinus halepensis

Allergenicity 1/4Blooms spring

Coast live oak

Quercus agrifolia

Allergenicity 4/4Blooms spring

Leaf plum purple

Prunus cerasifera

Allergenicity 1/4Blooms spring

London plane

Platanus acerifolia

Allergenicity 4/4Blooms spring

Evergreen pear

Pyrus kawakamii

Allergenicity 1/4Blooms spring

Holly oak

Quercus ilex

Allergenicity 4/4Blooms spring

London plane bloodgood

Platanus acerifolia

Allergenicity 4/4Blooms spring

Shamel ash

Fraxinus uhdei

Allergenicity 4/4Blooms spring

Glossy privet

Ligustrum lucidum

Allergenicity 2/4Blooms spring

Japanese black pine

Pinus thunbergiana

Allergenicity 1/4Blooms spring

Common questions

What is the pollen count in Ontario, CA today?

Ontario, CA is at a very high 5 out of 5 on the Universal Pollen Index today, driven mainly by tree pollen. Over the next five days it ranges from 1 to 5 of 5.

Is tree pollen high in Ontario, CA right now?

Tree pollen is very high today at 5 of 5. Most allergy sufferers will have symptoms.

What plants are causing allergies in Ontario, CA?

The main sources right now are Plane, Oak, Ash, Schinus, and Pine.