Watertown, South Dakota pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Watertown, South Dakota is moderate; ragweed is moderate; grass and mugwort are low.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed remains moderate, grass no longer expected, mugwort no longer expected.
7-Day Trend
Over the next week grass, mugwort, and ragweed will increase.
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Pollen Risk
Today - 20 September
| Pollen species | Level | Value |
|---|---|---|
| Alder (Alnus) | None | 0/100 |
| Birch (Betula) | None | 0/100 |
| Hazel (Corylus) | None | 0/100 |
| Cypress (Cupressaceae) | None | 0/100 |
| Grass (Poaceae) | Low | 11/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 7/100 |
| Ragweed (Ambrosia) | Moderate | 49/100 |
Tomorrow - 21 September
| Pollen species | Level | Value | 7-Day Trend |
|---|---|---|---|
| Alder (Alnus) | None | 0/100 | — |
| Birch (Betula) | None | 0/100 | — |
| Hazel (Corylus) | None | 0/100 | — |
| Cypress (Cupressaceae) | None | 0/100 | — |
| Grass (Poaceae) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Moderate | 29/100 |
Local Environmental Conditions
The vegetation around Watertown, on the glacial lakes region of northeast South Dakota, is dominated by shortgrass prairie and cottonwood along the lakes, with farmland crops adding further seasonal pollen exposure. Counts here rise and fall with the same broad rhythm as other places sharing this setting. Nearby towns with similar terrain tend to see a broadly similar pattern.
In Watertown, pollen season begins with elm and cottonwood starting in March with ash joining in and continuing through April. A grass pollen peak follows through May and June; ragweed and mugwort extend the season into September. Wide-open plains terrain lets pollen travel long distances on the prevailing wind, shaping conditions across the city.
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Frequently Asked Questions About Pollen in South Dakota
Is pollen high in Watertown, South Dakota right now?
On 20 September 2026, overall pollen levels in Watertown, South Dakota are moderate. Ambrosia is the main contributor to airborne pollen, while artemisia and grass remain at lower levels
Will pollen levels change in Watertown, South Dakota tomorrow?
On 21 September 2026, pollen conditions in Watertown, South Dakota will be different from today, with ambrosia at moderate levels
Is pollen expected to decrease in Watertown, South Dakota this week?
According to the five-day outlook, ambrosia, artemisia, and grass pollen levels will increase later in the week.
Which pollen types are currently active in Watertown, South Dakota?
On 20 September 2026, Ambrosia is the dominant pollen source in Watertown, South Dakota. artemisia and grass are also present but at lower levels.
When is pollen season in Watertown, South Dakota?
How often is the Watertown, South Dakota pollen forecast updated?
The Watertown, South Dakota pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Watertown, South Dakota come from nearby or far away?
Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.
Are pollen levels in Watertown, South Dakota based on measurements or forecasts?
Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.
Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in Watertown, South Dakota, modern forecasts combine recent measurements, weather data, and information about local vegetation.
This allows us to estimate pollen levels for today and the coming days, not just report the past.
Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.
Understanding the Scale
The 0–100 scores represent risk levels, not direct measurements of pollen or air pollutant concentrations. Higher scores indicate higher risk. Pollen and air quality use different thresholds.
Pollen
| None | 0 | No or negligible risk of exposure. Pollen/mold exposure is expected to be minimal. |
| Low | 0-25 | Low risk of exposure. Small amounts of pollen or mold spores may be present. |
| Moderate | 25-50 | Moderate risk of exposure. Pollen/mold exposure is expected to be noticeable. |
| High | 50-75 | High risk of exposure. Elevated pollen/mold exposure is expected. |
| Very High | 75-100 | Very high risk of exposure. Pollen/mold exposure is expected to be at or near its highest levels. |
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Get 15-day pollen forecasts with morning, afternoon and evening detail, plus 5-day air quality forecasts. Explore interactive pollen risk maps, estimated pollen season start, route profiles and a symptoms diary.
Features and forecast availability vary by region. Currently covering Europe, the contiguous US, southern Canada, South Africa, Australia, Indonesia (Java & Bali), Brazil, Paraguay, Uruguay and the Buenos Aires area.
Developed with support from the European Space Agency (ESA) Business Applications and Space Solutions (BASS).
