When is pollen worst in Gresham?

Gresham runs the classic three-wave calendar: tree pollen Feb–May, grass Apr–Jul, then ragweed Aug–Oct. The two worst stretches are the spring tree peak and the late-summer ragweed peak. Currently, grass pollen is what's driving counts this month.

What's in the air in Gresham right now?

In June, grass pollen is in season in Gresham — the dominant allergen you're likely reacting to right now. A live count, when available, confirms the day's actual reading; this reflects the typical peak windows for Gresham's mild, wet Pacific Northwest climate.

Is tree or grass pollen higher in Gresham in spring?

In spring, tree pollen leads in Gresham — trees pollinate Feb–May, ahead of grass (Apr–Jul). 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 Gresham's pollen season distinctive?

Gresham sits in the mild, wet Pacific Northwest zone, which means a mild, wet pattern in which a long grass season is usually the bigger problem than the early tree burst, and ragweed stays light. That shapes when symptoms hit and which allergen to watch.

How do I reduce pollen exposure in Gresham?

Through Gresham's peak windows (tree Feb–May, grass Apr–Jul, 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.

What pollen index counts as high?

Pollen is reported on a categorical scale — None, Low, Moderate, High, and Very High. "High" and above means most allergy sufferers notice symptoms even with brief outdoor exposure, and sensitized people should limit time outside and pre-medicate. "Low" to "Moderate" usually only affects highly sensitive individuals.

Gresham, Oregon Pollen Count

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

Gresham, OR · Pollen season

In June, grass pollen is in season in Gresham — the dominant allergen you're likely reacting to right now.

Based on the seasonal pollen calendar for this region.

Pollen by type this season

TreeOut of seasonpeaks Feb–May
GrassIn seasonpeaks Apr–Jul
Weed / RagweedOut of seasonpeaks Aug–Oct

Gresham pollen calendar

Typical peak months for each pollen type in this climate region. The highlighted column is the current month.

JFMAMJJASOND

TreeFeb–May

GrassApr–Jul

WeedAug–Oct

How Gresham’s pollen count works

The calendar above is tuned to Gresham’s mild, wet Pacific Northwest climate, not a national average: tree pollen peaks Feb–May, grass Apr–Jul, and ragweed Aug–Oct here. Those windows are why grass pollen is the one in season in Gresham right now.

No live count is wired up for Gresham today, so the seasonal calendar above is your guide to which allergen is in season. Counts run highest on warm, dry, windy mornings and drop after rain, which washes pollen out of the air — reported on the None / Low / Moderate / High / Very High scale.

Frequently asked

When is pollen worst in Gresham?: Gresham runs the classic three-wave calendar: tree pollen Feb–May, grass Apr–Jul, then ragweed Aug–Oct. The two worst stretches are the spring tree peak and the late-summer ragweed peak. Currently, grass pollen is what's driving counts this month.
What's in the air in Gresham right now?: In June, grass pollen is in season in Gresham — the dominant allergen you're likely reacting to right now. A live count, when available, confirms the day's actual reading; this reflects the typical peak windows for Gresham's mild, wet Pacific Northwest climate.
Is tree or grass pollen higher in Gresham in spring?: In spring, tree pollen leads in Gresham — trees pollinate Feb–May, ahead of grass (Apr–Jul). 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 Gresham's pollen season distinctive?: Gresham sits in the mild, wet Pacific Northwest zone, which means a mild, wet pattern in which a long grass season is usually the bigger problem than the early tree burst, and ragweed stays light. That shapes when symptoms hit and which allergen to watch.
How do I reduce pollen exposure in Gresham?: Through Gresham's peak windows (tree Feb–May, grass Apr–Jul, 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.
What pollen index counts as high?: Pollen is reported on a categorical scale — None, Low, Moderate, High, and Very High. "High" and above means most allergy sufferers notice symptoms even with brief outdoor exposure, and sensitized people should limit time outside and pre-medicate. "Low" to "Moderate" usually only affects highly sensitive individuals.

More for Gresham

See the full Gresham, OR weather forecast — hour-by-hour outlook, NOAA radar, satellite, and air quality.

Pollen by type this season

Gresham pollen calendar

How Gresham’s pollen count works

Frequently asked

More for Gresham

Pollen counts nearby in Oregon