ANN ARBOR, MI

Overview:
Ann Arbor is situated about 42 miles west of Detroit. The Huron River runs through the city, providing drinking water and recreational opportunities. Ann Arbor is in a forested area but is also in a productive region for agriculture and fruit-producing. Ann Arbor’s climate is mostly continental and is strongly influenced by the movement of high- and low-pressure systems across the continent.

Ann Arbor experiences larger seasonal temperature ranges than areas closer to the Great Lakes, which have moderated temperatures. Prevailing westerly winds deliver some lake effect precipitation to the area, but it is essentially limited to increased cloudiness during the late fall and early winter. While the day-to-day weather is highly variable, prolonged periods of hot, humid weather in the summer or extreme cold during the winter are relatively uncommon. Precipitation is well distributed throughout the year, although the wettest months of the year tend to occur during the warm season. Summer precipitation comes mainly from afternoon thunderstorms.

State/ Province ID: MI

Station ID: C00200230

Directory Name: ANN_ARBOR_U_OF_MICH_HCN_MI_C00200230

Elevation: 274.30m

Climatology PDF: Array

The resources presented here were developed in cooperation with the Office of the Michigan State Climatologist using data from the National Climatic Data Center. For more information regarding our data sources, quality control, and methodology, please see our Historical Climatologies: Quality Control reference guide.

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Recent Climate Summary, 1991-2020

Average Temperature50.1°F10.0°C
Average Low Temperature40.7°F4.8°C
Average High Temperature59.5°15.3°C
Days/Year that exceed 90°F9.2 
Days/Year that fall below 32°F121.2 
Lowest Annual Average Temperature47.5°F8.6°C
Highest Annual Average Temperature53.4°F11.9°C
Average Annual Total Precipitation38.3 in97.2 cm
Lowest Annual Precipitation Total27.0 in68.6 cm
Highest Annual Precipitation Total51.1 in129.8 cm
Days/Year that exceed 1.25" of Precipitation3.5 

Temperature

Click on the following links to be taken to the corresponding portion of the page.

  • Monthly Average Temperature
  • How Temperatures are Changing
    • Changes in Average Temperature – Includes a summary table of the average annual and seasonal temperature changes, and time series graphs of how the annual low, average, and high temperatures compare to the long term average plotted for every year on record.
    • Cold Temperatures – View time series plots of the number of days per year below 32°F and the number of heating degree days (?) per year to see how cold days are changing.
    • Hot Temperatures – View time series plots of the number of days per year above 90°F and the number of cooling degree days (?) per year to see how hot days are changing.
    • Growing Season Changes – View a time series of the annual number of days in the freeze-free period (?).

Monthly Average Temperature

Changes in Average Temperature, 1951-2024.

 °F°C
Annual average temperature1.20.7
Winter average temperature2.41.3
Spring average temperature1.60.9
Summer average temperature0.20.1
Fall average temperature0.50.3

Annual High and Low Temperature Departure

Heating/ Cooling Degree Days Narrative:

This is the heating/cooling narrative for Ann Arbor.

Cold Temperatures

¹Heating Degree Days (HDDs) are indexed units, not actual days, that roughly describe the demand to heat a building. HDDs accumulate on days colder than 65°F when heating is required. Every degree below 65°F is added to the annual total for an annual HDD value, which is plotted in the figure.

Hot Temperatures

²Cooling Degree Days (CDDs) are indexed units, not actual days, that roughly describe the demand to cool a building. CDDs accumulate on days warmer than 65°F when cooling is required. Every degree above 65°F is added to the annual total for an annual CDD value, which is plotted in the figure.

Growing Season Changes

Freeze-Free Narrative:

This is the freezefree narrative for Ann Arbor

Precipitation

Click on the following links to be taken to the corresponding portion of the page.

  • Monthly Average Precipitation – View a graph of the monthly low, average, and high precipitation climatology (average) of the past 30 years
  • How Precipitation is Changing
    • Changes in Total Precipitation – Includes a summary table of the average annual and seasonal precipitation changes.
    • Heavy Precipitation – View a time series graph of how annual number of days receiving more than 1, 1.25, 1.5, 1.75, and 2 inches of precipitation are changing over the period of record.

Monthly Average Precipitation

Changes in Average Precipitation, 1951-2024.

 in.cm.%
Annual total precipitation14.236.046.80
Winter total precipitation3.89.765.90
Spring total precipitation3.38.339.10
Summer total precipitation4.210.745.10
Fall total precipitation2.56.536.90

Heavy Precipitation