Louisville, CO Pollen Count Today

What is the Louisville pollen count today?

The Louisville pollen count today is 26 out of 100 (Low) on the Pollen Atlas Total Pollen Index, driven mainly by Ragweed.

Short answer for anyone searching pollen count today Louisville: this page is updated every morning with the day’s modelled reading.

Louisville allergies today

Louisville allergies today are set by the same reading as the pollen count above: the Total Pollen Index is 26 (Low), driven mainly by Ragweed. When people ask about Louisville allergies, this is the number that answers them — one daily index built from today’s tree, grass, weed and mold readings for Louisville.

Allergies in Louisville follow the Colorado 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 Louisville 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 Louisville allergy forecast: today reads 26 (Low), and the day-by-day outlook shows whether Louisville 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 Louisville today records is this same combined reading — tree, grass, weed and mold in one index.

The Louisville allergy count today is 26 (Low) — the same Total Pollen Index as the pollen count above, in one combined reading.

Pollen count today Louisville: the 5-day forecast

Pollen Atlas forecasts Louisville’s pollen count to peak on Wednesday at 28 (Low) over the next 5 days.

Pollen by type in Louisville

• Louisville tree pollen count
• Louisville grass pollen count
• Louisville ragweed pollen count

What is driving Louisville’s pollen today

The shape of today’s 26 (Low) is set by weed pollen at 34 (Low on its own scale) — about 96% of the four category readings added together, 33 points clear of the next category, tree pollen at 1. 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 Colorado 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 Louisville, so the drivers have to be read from the category split above. The Colorado guide’s account of Colorado names juniper, arriving ahead of the local tree season, and the ragweed and sagebrush-family weeds of late summer — 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 26 to 28, never changing band. Today’s 26 sits 0 points below the window’s average of 26.4 — a steady window, in which one day reads much like the next.

Plants affecting Louisville now

Detailed plant-by-plant readings for Louisville 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 1 (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 34 (Low).

In the Mountain West pattern, the plants that typically shape this city’s year are spring trees and late-spring grasses in a compressed warm-season window — 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.

Louisville pollen through the year

The Louisville pollen year runs in chapters, set by the Mountain West pattern and the Colorado calendar. Trees come first: juniper can arrive in late winter, and the main tree wave builds in spring — as late as April at Denver’s altitude. Grasses take the middle of the year: grasses follow in a compressed early-summer run. Weeds close it out: ragweed and sagebrush-family weeds close the year from late summer.

The Colorado allergy season guide names juniper, arriving ahead of the local tree season, and the ragweed and sagebrush-family weeds of late summer. Altitude compresses Colorado’s season rather than removing it: the waves arrive late — Denver’s tree pollen typically builds in April — and end with early frosts, but they run in a tight sequence. The season ends with the first hard frosts, which stop the late-summer weeds — Denver usually reaches frost in fall, while mountain towns can frost far earlier.

November falls between the main chapters of the Colorado 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 Colorado year, February to October — leaving a quiet gap of roughly 3 months in the depth of the off-season. The full calendar is set out in the Colorado allergy season guide.

How to read this index

Pollen Atlas reports the Louisville 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.

Louisville in today’s national picture

At 26 (Low), Louisville ranks joint 29974th 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 Louisville: Paragon Estates, CO (2 miles away) reads 25 (Low); Superior, CO (3 miles away) reads 26 (Low); Lafayette, CO (3 miles away) reads 26 (Low). Louisville reads 1 point higher than its nearest tracked neighbour today. Across Colorado’s 479 tracked cities, today runs from 5 in Parker to 33 in Cathedral.

Pollen totals are population numbers; symptoms are personal. The same reading can leave one Louisville resident untouched and floor another, depending on which pollens they are sensitised to. If this pattern finds you every season, allergists in Louisville, CO 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.

Louisville in its local area

Louisville is a city in Boulder County, Colorado. Its population is 20,788 (ACS 2023).

Across Colorado’s 479 tracked cities, Louisville ranks joint 40th today.

Like every Pollen Atlas city page, the Louisville, CO pollen count is refreshed each morning.

Nearby cities

• Paragon Estates pollen count (2 miles away)
• Superior pollen count (3 miles away)
• Lafayette pollen count (3 miles away)
• Broomfield pollen count (5 miles away)
• Valmont pollen count (6 miles away)
• Leyner pollen count (6 miles away)

From Pollen Atlas News

• Colorado allergy season
• Ragweed season