Ann Arbor’s climate is mostly continental and is strongly influenced by the movement of high and low pressure systems across the continent. It 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.
ANN ARBOR U OF MICH
Recent Climate Summary: 1981-2010
|Average Low Temperature||40.4°F||4.7°C|
|Average High Temperature||59.1°F||15.1°C|
|Days/Year that exceed 90°F||8.4|
|Days/Year that fall below 32°F||122.0|
|Lowest Annual Average Temperature||47.8°F||8.8°C|
|Highest Annual Average Temperature||53.3°F||11.8°C|
|Average Annual Total Precipitation||37.6 in||95.5 cm|
|Lowest Annual Precipitation Total||30.5 in||77.6 cm|
|Highest Annual Precipitation Total||47.6 in||120.8 cm|
|Days/Year that exceed 1.25" of Precipitation||3.7|
- Monthly Average Temperature
- How Temperatures are Changing
- Changes in Average Temperature – Includes a summary table of the average annual and seasonal temperature changes, time series graphs of how the annual low, average, and high temperatures compare to the long term average plotted for every year on record, and maps of how temperatures are changing across the Great Lakes region.
- 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, 1951-2017.
Maps of how seasonal temperatures are changing across the region are available here.
|Annual average temperature||1.1||0.6|
|Winter average temperature||1.4||0.8|
|Spring average temperature||1.9||1.1|
|Summer average temperature||0.7||0.4|
|Fall average temperature||0.7||0.4|
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.
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
- 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 and maps of how precipitation is changing across the Great Lakes region.
- 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
This is the narrative for the monthly temp precip - Ann Arbor.
Changes in Average Precipitation, 1951-2017.
Maps of how seasonal precipitation totals are changing across the region are available here.
|Annual total precipitation||13.0||33.0||42.90|
|Winter total precipitation||4.0||10.2||69.70|
|Spring total precipitation||2.9||7.4||34.90|
|Summer total precipitation||2.9||7.3||30.90|
|Fall total precipitation||2.9||7.4||41.90|