Longueuil, QC Pollen Count Today
Longueuil, QC · 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).
Longueuil, QC
Weeds Index
How active weeds pollen is today (0–100).
Longueuil, QC
Pollen Types
Pick a pollen subtype to update the species forecast
5-Day Longueuil Overall Pollen Forecast
Bars are colored by severity (Low/Moderate/High).
Pollen count Longueuil residents check each morning
The Longueuil pollen count today is 22 (Low). The main driver is Ragweed, with weed pollen at 29 today. The full split is tree pollen 0.6, grass pollen 0.6, weed pollen 29. The sections below break that headline number down by plant, by day and by what the band means in practice. 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 Longueuil page.
Fall is ragweed season across most of North America: ragweed plants release pollen from late summer into autumn, and weed pollen is typically the last major outdoor pollen category to fade as the weather cools. That pattern is why an autumn total is so often weed-led even when the headline number is low — tree and grass pollen have usually receded by then, leaving weed pollen, and on damp days mold, to make up most of what the index records. In the Northeast, autumn weed pollen typically winds down as colder nights arrive, so late-season totals can change quickly from week to week.
To see whether today’s pollen level holds, check the 5-day Longueuil pollen forecast below — it is currently mixed, with Tuesday the highest day in the window.
This is the pollen count Longueuil residents check each morning, built from the day’s tree, grass, weed and mold readings.
What is the Longueuil pollen count today?
The Longueuil pollen count today is 22 out of 100 (Low) on the Pollen Atlas Total Pollen Index, driven mainly by Ragweed.
Short answer for anyone searching pollen count today Longueuil: this page is updated every morning with the day’s modelled reading.
Longueuil allergies today
Longueuil allergies today are set by the same reading as the pollen count above: the Total Pollen Index is 22 (Low), driven mainly by Ragweed. When people ask about Longueuil allergies, this is the number that answers them — one daily index built from today’s tree, grass, weed and mold readings for Longueuil.
Allergies in Longueuil follow the Quebec 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 Longueuil 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 Longueuil allergy forecast: today reads 22 (Low), and the day-by-day outlook shows whether Longueuil 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 Longueuil today records is this same combined reading — tree, grass, weed and mold in one index.
The Longueuil allergy count today is 22 (Low) — the same Total Pollen Index as the pollen count above, in one combined reading.
Pollen count today Longueuil: the 5-day forecast
| Day | Total Pollen Index | Band |
|---|---|---|
| Saturday, November 7 | 22 | Low |
| Sunday, November 8 | 14 | Low |
| Monday, November 9 | 21 | Low |
| Tuesday, November 10 | 31 | Low |
| Wednesday, November 11 | 31 | Low |
Pollen Atlas forecasts Longueuil’s pollen count to peak on Tuesday at 31 (Low) over the next 5 days.
Pollen by type in Longueuil
What is driving Longueuil’s pollen today
The shape of today’s 22 (Low) is set by weed pollen at 29 (Low on its own scale) — about 96% of the four category readings added together, 28.4 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 Quebec weed chapter runs August to October — 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 Longueuil, so the drivers have to be read from the category split above — it shows how much of today’s total each category is actually carrying, and plant detail returns here automatically on any day the feed includes it.
Across the five-day window the Total Pollen Index runs from 14 to 31, never changing band. Today’s 22 sits 2 points below the window’s average of 23.8 — a moving window, worth reading day by day rather than from the average.
Plants affecting Longueuil now
Detailed plant-by-plant readings for Longueuil 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 29 (Low).
In the Northeast pattern, the plants that typically shape this city’s year are spring trees, late-spring grasses and late-summer ragweed — 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.
Longueuil pollen through the year
The Longueuil pollen year runs in chapters, set by the Northeast pattern and the Quebec calendar. Trees come first: trees open in late March and build to an oak-led peak in May. Grasses take the middle of the year: grasses hold from late May into July. Weeds close it out: ragweed builds from mid-August, peaks in September, and is ended by the first hard frost. Mold tracks the region’s humidity rather than a flowering calendar, and it fills the gaps between chapters.
No Quebec allergy season guide is published yet, so this page does not single out signature pollens for Longueuil — the calendar above is the Northeast regional pattern, and the plant detail on this page names what today’s feed actually records.
November falls between the main chapters of the Quebec 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 8 months of the Quebec year, March to October — a compressed season, which is why its chapters arrive in quick succession. No Quebec allergy season guide is published yet — this calendar follows the Northeast regional pattern. See Longueuil pollen count rankings and Longueuil on the pollen heatmap.
How to read this index
Pollen Atlas reports the Longueuil 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 even in a month when Longueuil, QC pollen is usually more active. 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.
Longueuil in today’s US & Canada picture
At 22 (Low), Longueuil ranks joint 43357th of the 90896 cities Pollen Atlas tracks today — in the middle of the combined US & Canada table. The highest reading on the combined table 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 Longueuil: Brossard, QC (4 miles away) reads 22 (Low); Montréal, QC (8 miles away) reads 28 (Low); Laval, QC (15 miles away) reads 25 (Low). Longueuil reads exactly level with its nearest tracked neighbour today. Across Quebec’s 21 tracked cities, today runs from 5 in Quebec City to 28 in Montréal.
Pollen totals are population numbers; symptoms are personal. The same reading can leave one Longueuil resident untouched and floor another, depending on which pollens they are sensitised to. If this pattern finds you every season, allergists in Longueuil, QC 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.
Longueuil in its local area
Longueuil is in Montérégie, Quebec, Canada. Its population is 229,330 (GeoNames).
Across Quebec’s 21 tracked cities, Longueuil ranks joint 3rd today.
Like every Pollen Atlas city page, the Longueuil, QC pollen count is refreshed each morning.
Nearby cities
- Brossard pollen count (4 miles away)
- Montréal pollen count (8 miles away)
- Laval pollen count (15 miles away)
- Saint-Jean-sur-Richelieu pollen count (16 miles away)
- Repentigny pollen count (17 miles away)
- Châteauguay pollen count (17 miles away)
From Pollen Atlas News
See how Longueuil 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).