Ontario, OR Pollen Count Today
Ontario, OR · Updated Saturday, November 7, 2026
Pollen Overview
Today's overall pollen level and the dominant type (trees, weeds, grass, or mold).
Total Pollen Index
The combined pollen level across all types (0–100).
Ontario, OR
Weeds Index
How active weeds pollen is today (0–100).
Ontario, OR
Pollen Types
Pick a pollen subtype to update the species forecast
5-Day Ontario Overall Pollen Forecast
Bars are colored by severity (Low/Moderate/High).
Pollen count Ontario residents check each morning
The Ontario pollen count today is 25 (Low). The main driver is Ragweed, with weed pollen at 33 today. That total sits on a narrow base: weed pollen is 33 while tree pollen is just 0.6 and grass pollen 0.6. Plant-by-plant detail for Ontario, OR follows, along with the outlook for the days ahead. Pollen Atlas updated this count on Saturday, November 7, 2026.
A Low band on the Pollen Atlas index means the Total Pollen Index has stayed in the lower part of the 0–100 scale. Readings in this band are built from low individual category values rather than from one large spike, and the category split above matters more than the headline number: a low total can still contain one category, such as weed pollen or mold, reading noticeably higher than the rest, which is why the split is printed on every Ontario page.
In the Pacific Northwest, the main outdoor pollen activity is concentrated in spring and early summer — trees first, then grasses — and readings outside that window are commonly low across every category. Cool-season pages in this region are therefore often defined by what is absent: zero or near-zero tree and grass values, with any remaining total carried by small weed or mold readings. That quiet pattern is itself useful information, and it is reported here exactly as modelled.
To see whether today’s pollen level holds, check the 5-day Ontario pollen forecast below — it is currently holding, with Saturday the highest day in the window.
This is the pollen count Ontario residents check each morning, built from the day’s tree, grass, weed and mold readings.
What is the Ontario pollen count today?
The Ontario pollen count today is 25 out of 100 (Low) on the Pollen Atlas Total Pollen Index, driven mainly by Ragweed.
Short answer for anyone searching pollen count today Ontario: this page is updated every morning with the day’s modelled reading.
Ontario allergies today
Ontario allergies today are set by the same reading as the pollen count above: the Total Pollen Index is 25 (Low), driven mainly by Ragweed. When people ask about Ontario allergies, this is the number that answers them — one daily index built from today’s tree, grass, weed and mold readings for Ontario.
Allergies in Ontario follow the Oregon calendar set out below — the chapters, the plants behind them, and the 5-day forecast on this page show whether today is typical for the season or an exception to it. If you are checking allergies today in Ontario before heading outdoors, the split at the top of this page is the part to read: it shows which pollen is doing the work today, not just how high the total sits.
Read the five-day table on this page as the Ontario allergy forecast: today reads 25 (Low), and the day-by-day outlook shows whether Ontario allergies are set to ease or build across the week — the days to plan outdoor time around are the ones where the index steps down, not just today.
In practice, the allergy count Ontario today records is this same combined reading — tree, grass, weed and mold in one index.
The Ontario allergy count today is 25 (Low) — the same Total Pollen Index as the pollen count above, in one combined reading.
Pollen count today Ontario: the 5-day forecast
| Day | Total Pollen Index | Band |
|---|---|---|
| Saturday, November 7 | 25 | Low |
| Sunday, November 8 | 25 | Low |
| Monday, November 9 | 22 | Low |
| Tuesday, November 10 | 22 | Low |
| Wednesday, November 11 | 22 | Low |
Pollen Atlas forecasts Ontario’s pollen count to peak on Saturday at 25 (Low) over the next 5 days.
Pollen by type in Ontario
What is driving Ontario’s pollen today
The shape of today’s 25 (Low) is set by weed pollen at 33 (Low on its own scale) — about 96% of the four category readings added together, 32.4 points clear of the next category, tree pollen at 0.6. A weed-led total is the classic late-year shape: tree and grass pollen have usually receded, leaving weed pollen — and on damp days mold — to make up most of what the index records. Weed pollen leading in November runs against the usual calendar — the Oregon weed chapter runs August to September — so today’s lead is the model outranking the pattern, and this page reports the modelled reading first.
Plant-level detail is not in today’s feed for Ontario, so the drivers have to be read from the category split above. The Oregon guide’s account of Oregon names alder and hazelnut early, then the Willamette Valley’s seed grasses — the pollens behind readings of this shape in this state — and the split shows how much of today’s total each category is actually carrying.
Across the five-day window the Total Pollen Index runs from 22 to 25, never changing band. Today’s 25 sits 2 points above the window’s average of 23.2 — a steady window, in which one day reads much like the next.
Plants affecting Ontario now
Detailed plant-by-plant readings for Ontario were not returned in today\u2019s source data, so this section summarises the pollen types the index above is built from instead of listing individual plants.
Tree pollen is one of the categories with a non-zero reading today, at 0.6 (Low).
Grass pollen is one of the categories with a non-zero reading today, at 0.6 (Low).
Weed pollen is one of the categories with a non-zero reading today, at 33 (Low).
In the Pacific Northwest pattern, the plants that typically shape this city’s year are spring trees and late-spring grasses in the Pacific Northwest pattern — named here as regional context only, not as today\u2019s measurements.
Plant detail returns here automatically on any day the source data includes it.
Every pollen type, with photos and seasons: the pollen directory.
Ontario pollen through the year
Chapter by chapter, the Ontario pollen year runs like this:
- Alder and hazelnut can start in January west of the Cascades, with maple and oak following through April and May.
- Grasses run from May, peaking in late spring and early summer.
- Weeds are the minor act — sagebrush and tumbleweed east of the Cascades carry into September.
- Mold is the wet-season constant west of the Cascades, where rain crashes counts and the season restarts on the first dry, mild day.
The Oregon allergy season guide names alder and hazelnut early, then the Willamette Valley’s seed grasses. The Willamette Valley grows almost two-thirds of the United States’ cool-season grass seed, and its grass peak ends when the mid-summer harvest cuts the fields and removes the source. East of the Cascades, western juniper’s late-winter-to-spring pollen opens a shorter, compressed high-desert season.
November falls between the main chapters of the Oregon pollen year — the tail of one and the approach of the next — so the calendar alone explains little today, and the modelled split above carries the story. Between them, the three chapters cover 9 months of the Oregon year, January to September — leaving a quiet gap of roughly 3 months in the depth of the off-season. The full calendar is set out in the Oregon allergy season guide.
How to read this index
Pollen Atlas reports the Ontario pollen count on a Total Pollen Index from 0 to 100, built from separate tree, grass and weed readings. The total is a summary, not an average of the three: a single strong category can lift it, and three quiet categories can hold it down whatever the month. Index values are a modelled pollen risk index computed by Pollen Atlas from open weather, vegetation and phenology data, calibrated against CDC/NAB season data, with plant detail by the Google Pollen API. The index is a modelled 0–100 scale, not a measured count, and figures update through the day, so a morning and an evening visit to this page can legitimately show different numbers.
Ontario in today’s national picture
At 25 (Low), Ontario ranks joint 33676th of the 90896 cities Pollen Atlas tracks today — in the middle of the national table. The highest reading in the country today is Beja, Portugal at 52, and the lowest is Los Ángeles de San Rafael, Spain at 5. The whole table spans 47 points today — a wide-open day, when the top and bottom of the table are effectively in different seasons.
Around Ontario: Fruitland, ID (3 miles away) reads 26 (Low); Payette, ID (5 miles away) reads 23 (Low); New Plymouth, ID (9 miles away) reads 28 (Low). Ontario reads 1 point lower than its nearest tracked neighbour today. Across Oregon’s 426 tracked cities, today runs from 5 in Bend to 30 in Junction City.
Pollen totals are population numbers; symptoms are personal. The same reading can leave one Ontario resident untouched and floor another, depending on which pollens they are sensitised to. If this pattern finds you every season, allergists in Ontario, OR can test whether tree, grass, weed or mold is the category that matters for you — the four readings at the top of this page are the starting point for that conversation.
Ontario in its local area
Ontario is a city in Malheur County, Oregon. Its population is 11,728 (ACS 2023).
Across Oregon’s 426 tracked cities, Ontario ranks joint 34th today.
Like every Pollen Atlas city page, the Ontario, OR pollen count is refreshed each morning.
Nearby cities
- Nyssa pollen count (10 miles away)
- Vale pollen count (13 miles away)
- Annex pollen count (14 miles away)
- Adrian pollen count (20 miles away)
- Huntington pollen count (27 miles away)
- Brogan pollen count (31 miles away)
From Pollen Atlas News
See how Ontario ranks in today's pollen count rankings — the worst cities for allergies today
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).