When is pollen worst in St. Petersburg?

The late-summer ragweed run is the headline in St. Petersburg: weed pollen peaks Aug–Nov, the longest and most punishing window of the year here. Tree pollen comes first (Jan–Mar) and grass bridges the gap (Mar–Aug), but it's the ragweed stretch that floors most sufferers. Currently, ragweed pollen is in season.

What's in the air in St. Petersburg right now?

In September, ragweed pollen is in season in St. Petersburg, peaking Aug–Nov. On St. Petersburg's warm, humid subtropical Southeast calendar the typical September level is High, led by ragweed pollen — a seasonal estimate, not a live count.

Is tree or grass pollen higher in St. Petersburg in spring?

In spring, tree pollen leads in St. Petersburg — trees pollinate Jan–Mar, ahead of grass (Mar–Aug). The handoff is the tail of the tree window: tree counts taper as grass climbs, so an early-spring flare is more likely tree pollen and a late-spring one more likely grass.

What makes St. Petersburg's pollen season distinctive?

St. Petersburg sits in the warm, humid subtropical Southeast zone, which means an unusually long, overlapping season — the warm climate stretches grass across much of the year and pushes ragweed deep into autumn. That shapes when symptoms hit and which allergen to watch.

How do I reduce pollen exposure in St. Petersburg?

Through St. Petersburg's peak windows (tree Jan–Mar, grass Mar–Aug, ragweed Aug–Nov), keep windows shut and run AC on recirculate; counts run highest on dry, warm, windy mornings, so push outdoor activity to late afternoon or just after rain, which clears pollen from the air. A HEPA purifier indoors, a saline rinse after being outside, showering before bed, and starting antihistamines a week or two before your worst local window all measurably cut symptoms.

When does the next pollen season start in St. Petersburg?

Tree pollen is next in St. Petersburg: it opens around week 1 (early January), peaks around week 7, and runs about 91 days.

What is the allergy forecast in St. Petersburg today?

With no live reading for St. Petersburg today, its allergy forecast is the seasonal estimate above: a typical September level of High, led by ragweed pollen.

St. Petersburg, Florida Pollen Count & Allergy Forecast

St. Petersburg pollen count and allergy forecast — tree, grass, and ragweed seasons and what’s pollinating now

St. Petersburg, FL · Pollen season

In September, ragweed pollen is in season in St. Petersburg, peaking Aug–Nov.

Based on the seasonal pollen calendar for this region.

St. Petersburg on the WeatherStory Allergy Index

St. Petersburg isn't one of the 100 metros on the WeatherStory Allergy Index, but the nearest ranked metro — Tampa, FL, about 19 miles away — sits at #9 with a 335-day combined pollen season.

#9of 100nearest ranked metro

Load index: 42
Combined season: 335 days
Heaviest load: Grass · 183 days
Nearest ranked metro: Tampa, FL · ~19 mi

See the full 100 worst U.S. cities for pollen — a modeled seasonal load ranking (see methodology).

Typical now — Septemberseasonal estimate, not a live reading

Ragweed pollen typically leads in St. Petersburg in September, at an estimated High level.

Pollen by type this season

TreeOut of seasonpeaks Jan–Mar
GrassOut of seasonpeaks Mar–Aug
Weed / RagweedIn seasonpeaks Aug–Nov

What pollinates near St. Petersburg

The tree, grass, and weed species that drive St. Petersburg’s pollen seasons, with each plant’s typical peak.

Trees

Oak Quercuspeaks March–April
Loblolly pine Pinus taedapeaks March–April
Pecan Carya illinoinensispeaks April–May
Sweetgum Liquidambar styracifluapeaks March–April
Mulberry Moruspeaks March–April
Elm Ulmuspeaks February–March

Grasses

Bermuda grass Cynodon dactylonpeaks May–September
Bahia grass Paspalum notatumpeaks May–September
Johnson grass Sorghum halepensepeaks June–August
Timothy Phleum pratensepeaks May–June

Weeds

Common ragweed Ambrosia artemisiifoliapeaks August–October
Giant ragweed Ambrosia trifidapeaks August–October
Pigweed Amaranthuspeaks August–September
English plantain Plantago lanceolatapeaks May–September

Species are the region’s common wind-pollinated plants; peak months are a seasonal estimate, not a measured count — see methodology.

St. Petersburg’s allergy year

Typical month-by-month pollen intensity for St. Petersburg, tuned to its latitude and climate region — darker means higher typical counts. The highlighted column is the current month.

JFMAMJJASOND

TreeJan–Mar

GrassMar–Aug

RagweedAug–Nov

How St. Petersburg compares to the U.S. average

Each colored bar is St. Petersburg’s typical season against the national-average window (grey). The offset is the per-city timing shift.

Tree~8 wks earlier

Grass~8 wks earlier

Ragweedabout average

“U.S. average” is the textbook tree Mar–May, grass May–Jul, ragweed Aug–Oct calendar. The shift is a phenology estimate (Hopkins’ bioclimatic law), not a measured count — see methodology.

How St. Petersburg’s pollen count works

The calendar above is tuned to St. Petersburg’s warm, humid subtropical Southeast climate, not a national average: tree pollen runs from week 1 (early January) to week 13 (late March), grass from week 10 (early March) to week 35 (late August), and ragweed from week 31 (early August) to week 48 (late November) here — a 335-day combined pollen season. Those windows are why ragweed pollen is the one in season in St. Petersburg right now.

No live count is wired up for St. Petersburg today, so the seasonal calendar above is your guide to which allergen is in season.

For the science behind St. Petersburg’s pollen seasons — how counts are measured, when each type peaks, and what the numbers mean — see the pollen count scale and the other pollen & allergy guides.

Frequently asked

When is pollen worst in St. Petersburg?: The late-summer ragweed run is the headline in St. Petersburg: weed pollen peaks Aug–Nov, the longest and most punishing window of the year here. Tree pollen comes first (Jan–Mar) and grass bridges the gap (Mar–Aug), but it's the ragweed stretch that floors most sufferers. Currently, ragweed pollen is in season.
What's in the air in St. Petersburg right now?: In September, ragweed pollen is in season in St. Petersburg, peaking Aug–Nov. On St. Petersburg's warm, humid subtropical Southeast calendar the typical September level is High, led by ragweed pollen — a seasonal estimate, not a live count.
Is tree or grass pollen higher in St. Petersburg in spring?: In spring, tree pollen leads in St. Petersburg — trees pollinate Jan–Mar, ahead of grass (Mar–Aug). The handoff is the tail of the tree window: tree counts taper as grass climbs, so an early-spring flare is more likely tree pollen and a late-spring one more likely grass.
What makes St. Petersburg's pollen season distinctive?: St. Petersburg sits in the warm, humid subtropical Southeast zone, which means an unusually long, overlapping season — the warm climate stretches grass across much of the year and pushes ragweed deep into autumn. That shapes when symptoms hit and which allergen to watch.
How do I reduce pollen exposure in St. Petersburg?: Through St. Petersburg's peak windows (tree Jan–Mar, grass Mar–Aug, ragweed Aug–Nov), keep windows shut and run AC on recirculate; counts run highest on dry, warm, windy mornings, so push outdoor activity to late afternoon or just after rain, which clears pollen from the air. A HEPA purifier indoors, a saline rinse after being outside, showering before bed, and starting antihistamines a week or two before your worst local window all measurably cut symptoms.
When does the next pollen season start in St. Petersburg?: Tree pollen is next in St. Petersburg: it opens around week 1 (early January), peaks around week 7, and runs about 91 days.
What is the allergy forecast in St. Petersburg today?: With no live reading for St. Petersburg today, its allergy forecast is the seasonal estimate above: a typical September level of High, led by ragweed pollen.