Today | Weather | Monday, July 20, 2026

Weather in Watertown, South Dakota

04:28 PM
Now
Cloudy Weather
88° F
Feels Like 88°
Precipitation 0 %
Wind 17 mph
UV Index (0 - 11+) 5
Humidity 36 %
Today
Cloudy Weather
Day 88°
Night 63°
Precipitation 1 %
Wind 14 mph
UV Index (0 - 11+) 9

Warning: High UV Index Today: 9

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

Watertown Weather Forecast Updated

8 minutes ago
Last updated on

Air Quality in Watertown

NOW
85 AQI
Moderate air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 16.1 µg/m³
PM10 16.52 µg/m³
O3 0.065 ppm
NO2 0.3 ppb
SO2 0.1 ppb
CO 0.13 ppm
NH3 1.48 µg/m³
NO 0.07 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is acceptable; however, for some pollutants, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

Show raw pollutant concentrations (µg/m³)
PM2.516.1 µg/m³
PM1016.52 µg/m³
O3128.18 µg/m³
NO20.59 µg/m³
SO20.2 µg/m³
CO144.65 µg/m³
NH31.48 µg/m³
NO0.07 µg/m³