Today | Weather | Thursday, May 21, 2026

Weather in Ann Arbor, Michigan

11:19 AM
Now
Cloudy Weather
52° F
Feels Like 55°
Precipitation 0 %
Wind 10 mph
UV Index (0 - 11+) 7
Humidity 55 %
Today
Cloudy Weather
Day 64°
Night 46°
Precipitation 0 %
Wind 10 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.

Ann Arbor Weather Forecast Updated

3 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (May 21, 2025)
Rainy Weather

Day

54°

Night

48°

Wind

8 mph

UV Index

2

Precipitation

100 %

Air Quality in Ann Arbor

NOW
41 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.22 µg/m³
PM10 2.82 µg/m³
O3 0.044 ppm
NO2 2.1 ppb
SO2 1.3 ppb
CO 0.11 ppm
NH3 3.25 µg/m³
NO 1.31 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 considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.52.22 µg/m³
PM102.82 µg/m³
O386.01 µg/m³
NO23.89 µg/m³
SO23.32 µg/m³
CO130.41 µg/m³
NH33.25 µg/m³
NO1.31 µg/m³