Olympia, Washington Pollen Count & Allergy Forecast
Olympia pollen count and allergy forecast — tree, grass, and ragweed seasons and what’s pollinating now
Olympia, WA · Pollen season
In September, ragweed pollen is in season in Olympia, peaking Aug–Oct.
Based on the seasonal pollen calendar for this region.
Olympia on the WeatherStory Allergy Index
Olympia isn't one of the 100 metros on the WeatherStory Allergy Index, but the nearest ranked metro — Seattle, WA, about 48 miles away — sits at #53 with a 274-day combined pollen season.
- Load index
- 30
- Combined season
- 274 days
- Heaviest load
- Tree · 122 days
- Nearest ranked metro
- Seattle, WA · ~48 mi
See the full 100 worst U.S. cities for pollen — a modeled seasonal load ranking (see methodology).
Ragweed pollen typically leads in Olympia in September, at an estimated Moderate level.
Pollen by type this season
- TreeOut of season
- GrassOut of season
- Weed / RagweedIn season
What pollinates near Olympia
The tree, grass, and weed species that drive Olympia’s pollen seasons, with each plant’s typical peak.
Trees
- Alder Alnuspeaks February–March
- Birch Betulapeaks March–April
- Western red cedar Thuja plicatapeaks March–April
- Douglas fir Pseudotsuga menziesiipeaks April–May
- Oak Quercuspeaks April–May
Grasses
- Perennial ryegrass Lolium perennepeaks May–July
- Orchard grass Dactylis glomeratapeaks May–July
- Timothy Phleum pratensepeaks June–July
- Kentucky bluegrass Poa pratensispeaks May–June
Weeds
- Common ragweed Ambrosia artemisiifoliapeaks August–September
- Plantain Plantagopeaks June–August
- Lamb's quarters Chenopodium albumpeaks July–September
- Sheep sorrel Rumex acetosellapeaks May–July
Species are the region’s common wind-pollinated plants; peak months are a seasonal estimate, not a measured count — see methodology.
Olympia’s allergy year
Typical month-by-month pollen intensity for Olympia, tuned to its latitude and climate region — darker means higher typical counts. The highlighted column is the current month.
How Olympia compares to the U.S. average
Each colored bar is Olympia’s typical season against the national-average window (grey). The offset is the per-city timing shift.
“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 Olympia’s pollen count works
The calendar above is tuned to Olympia’s mild, wet Pacific Northwest climate, not a national average: tree pollen runs from week 5 (early February) to week 22 (late May), grass from week 14 (early April) to week 30 (late July), 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 Olympia right now.
No live count is wired up for Olympia today, so the seasonal calendar above is your guide to which allergen is in season.
For the science behind Olympia’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 Olympia?
- Olympia 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, ragweed pollen is in season.
- What's in the air in Olympia right now?
- In September, ragweed pollen is in season in Olympia, peaking Aug–Oct. On Olympia's mild, wet Pacific Northwest 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 Olympia in spring?
- In spring, tree pollen leads in Olympia — 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 Olympia's pollen season distinctive?
- Olympia 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 Olympia?
- Through Olympia'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.
- When does the next pollen season start in Olympia?
- Tree pollen is next in Olympia: it opens around week 5 (early February), peaks around week 11, and runs about 122 days.
- What is the allergy forecast in Olympia today?
- With no live reading for Olympia today, its allergy forecast is the seasonal estimate above: a typical September level of Moderate, led by ragweed pollen.