When is pollen worst in Tucson?

Tree pollen jumps the gun in Tucson, opening as early as Jan–Apr while colder regions are still dormant. Grass follows Mar–Jun and ragweed closes the year Aug–Oct. The early tree start is the trap — symptoms can begin before you expect them. Currently, ragweed pollen is in season.

What's in the air in Tucson right now?

In September, ragweed pollen is in season in Tucson, peaking Aug–Oct. On Tucson's arid Southwest desert calendar the typical September level is Moderate, led by ragweed pollen — a seasonal estimate, not a live count.

Is tree or grass pollen higher in Tucson in spring?

In spring, tree pollen leads in Tucson — trees pollinate Jan–Apr, ahead of grass (Mar–Jun). 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 Tucson's pollen season distinctive?

Tucson sits in the arid Southwest desert zone, which means an early tree season and a comparatively light, short ragweed season — the dry desert air suppresses the weed load that hammers wetter regions. That shapes when symptoms hit and which allergen to watch.

How do I reduce pollen exposure in Tucson?

Through Tucson's peak windows (tree Jan–Apr, grass Mar–Jun, ragweed Aug–Oct), 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 Tucson?

Tree pollen is next in Tucson: it opens around week 1 (early January), peaks around week 7, and runs about 122 days.

What is the allergy forecast in Tucson today?

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

Tucson, Arizona Pollen Count & Allergy Forecast

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

Tucson, AZ · Pollen season

In September, ragweed pollen is in season in Tucson, peaking Aug–Oct.

Based on the seasonal pollen calendar for this region.

Tucson on the WeatherStory Allergy Index

Tucson ranks #90 of 100 U.S. metros on the WeatherStory Allergy Index, with a modeled load index of 30 and a 274-day combined pollen season — its heaviest load is tree pollen, running 122 days.

#90of 100

Load index: 30
Combined season: 274 days
Heaviest load: Tree · 122 days

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 Tucson in September, at an estimated Moderate level.

Pollen by type this season

TreeOut of seasonpeaks Jan–Apr
GrassOut of seasonpeaks Mar–Jun
Weed / RagweedIn seasonpeaks Aug–Oct

What pollinates near Tucson

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

Trees

Mountain cedar Juniperus asheipeaks January–February
Ashe juniper Juniperus asheipeaks January–February
Mesquite Prosopispeaks March–May
Cottonwood Populus fremontiipeaks February–March
Arizona ash Fraxinus velutinapeaks February–March
Olive Olea europaeapeaks March–April

Grasses

Bermuda grass Cynodon dactylonpeaks April–September
Johnson grass Sorghum halepensepeaks May–August
Grama grass Boutelouapeaks July–September
Salt grass Distichlis spicatapeaks May–July

Weeds

Careless weed Amaranthus palmeripeaks August–September
Russian thistle Salsola traguspeaks July–September
Sagebrush Artemisiapeaks August–September
Ragweed Ambrosiapeaks August–September

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

Tucson’s allergy year

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

JFMAMJJASOND

TreeJan–Apr

GrassMar–Jun

RagweedAug–Oct

How Tucson compares to the U.S. average

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

Tree~9 wks earlier

Grass~9 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 Tucson’s pollen count works

The calendar above is tuned to Tucson’s arid Southwest desert climate, not a national average: tree pollen runs from week 1 (early January) to week 17 (late April), grass from week 10 (early March) to week 26 (late June), and ragweed from week 31 (early August) to week 43 (late October) here — a 274-day combined pollen season. Those windows are why ragweed pollen is the one in season in Tucson right now.

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

For the science behind Tucson’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 Tucson?: Tree pollen jumps the gun in Tucson, opening as early as Jan–Apr while colder regions are still dormant. Grass follows Mar–Jun and ragweed closes the year Aug–Oct. The early tree start is the trap — symptoms can begin before you expect them. Currently, ragweed pollen is in season.
What's in the air in Tucson right now?: In September, ragweed pollen is in season in Tucson, peaking Aug–Oct. On Tucson's arid Southwest desert calendar the typical September level is Moderate, led by ragweed pollen — a seasonal estimate, not a live count.
Is tree or grass pollen higher in Tucson in spring?: In spring, tree pollen leads in Tucson — trees pollinate Jan–Apr, ahead of grass (Mar–Jun). 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 Tucson's pollen season distinctive?: Tucson sits in the arid Southwest desert zone, which means an early tree season and a comparatively light, short ragweed season — the dry desert air suppresses the weed load that hammers wetter regions. That shapes when symptoms hit and which allergen to watch.
How do I reduce pollen exposure in Tucson?: Through Tucson's peak windows (tree Jan–Apr, grass Mar–Jun, ragweed Aug–Oct), 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 Tucson?: Tree pollen is next in Tucson: it opens around week 1 (early January), peaks around week 7, and runs about 122 days.
What is the allergy forecast in Tucson today?: With no live reading for Tucson today, its allergy forecast is the seasonal estimate above: a typical September level of Moderate, led by ragweed pollen.