Conditions TodayMaps

Pollen Today for Largo, FL

Good

Mild weed pollen in Largo, FL today

Tree: Low · Grass: Low · Weed: Moderate

Moderate
weed pollen leading today
  • Tree pollenLow (UPI 2/5)

    UPI is the Universal Pollen Index, a 0–5 scale (0 none, 5 very high) that is comparable across pollen types and locations.

  • Grass pollenLow (UPI 2/5)
  • Weed pollenModerate (UPI 3/5)
  • TimingCounts peak 10am–3pm; lowest overnight and after rain
  • TipMorning hours tend to be higher

Data as of Oct 18, 2026

Coming Up

WedModerateGood
ThuModerateGood
FriLowGreat
SatHighOkay
SunModerateGood

What’s in the air in Largo right now

The pollen model for Largo currently tracks 3 active species — Ragweed (UPI 3/5), Elm (UPI 2/5), Grasses (UPI 2/5). Ragweed is the strongest source right now.

Looking at the 5-day forecast, weed pollen is expected to climb, peaking around Saturday.

Ragweed is a weed pollen source. A single ragweed plant can release about a billion pollen grains, and it dominates the late-summer-to-first-frost allergy season across most of the US.

Elm is a tree pollen source. Elm releases pollen in late winter and early spring, and some species pollinate again in fall.

Grasses is a grass pollen source. Grass is the most widespread pollen allergen in the country, typically peaking from late spring through midsummer — and lawn mowing stirs it up even outside the peak.

The tree, grass, and weed rows above roll these species into three groups, but knowing the exact species helps: if allergy testing showed what you react to, you can check whether your trigger is actually the one flying today.

Ragweed is the driver this time of year, and in Largo it has roughly 88 days left to run. Weed pollen doesn't stop on a calendar date — it stops when a hard frost kills the plants, and Largo's average first frost falls around January 14.

That is why the same ragweed season is weeks shorter in the northern states than in the South: identical plants, different frost dates. A single ragweed plant can release around a billion pollen grains, and they travel hundreds of miles on the wind, so a low local count doesn't guarantee a quiet day.

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