ANN ARBOR U OF MICH

Station ID: 
C00200230
Elevation: 
274.30m
Climatology PDF: 

Overview

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 welldistributed throughout the year, although the wettest months of the year tend to occur during the warm season. Summer precipitation comes mainly from afternoon thunderstorms.

Summary of Observed Changes

Rising average temperatures: Annual average temperatures warmed by 0.7°F from 1951-2014, slower than regional, national, and global rates. Average low and high temperatures have warmed at approximately the same pace.

Longer freeze-free season: Despite warming average temperatures, the freeze-free period of the year has actually shortened slightly, by approximately 4 days, from 1951-2014.

More precipitation: Total precipitation increased 44.2% (13.4 inches), from 1951 through 2014. Winter increases over that time exceed 75% (4.4 inches).

More heavy precipitation: The number of very heavy precipitation events has increased by 21.1% (comparing the 1951-1980 total to the 1981-2010 total).

Recent Climate Summary: 1981-2010

Average Temperature49.8°F9.9°C
Average Low Temperature40.4°F4.7°C
Average High Temperature59.1°F15.1°C
Days/Year that exceed 90°F8.4 
Days/Year that fall below 32°F122.0 
Lowest Annual Average Temperature47.8°F8.8°C
Highest Annual Average Temperature53.3°F11.8°C
Average Annual Total Precipitation37.6 in95.5 cm
Lowest Annual Precipitation Total30.5 in77.6 cm
Highest Annual Precipitation Total47.6 in120.8 cm
Days/Year that exceed 1.25" of Precipitation3.7 

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, 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

 

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Changes in Average Temperature, 1951-2017.

Maps of how seasonal temperatures are changing across the region are available here.

 °F°C
Annual average temperature1.10.6
Winter average temperature1.40.8
Spring average temperature1.91.1
Summer average temperature0.70.4
Fall average temperature0.70.4


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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.

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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.

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Growing Season Changes

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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 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.

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Changes in Average Precipitation, 1951-2017.

Maps of how seasonal precipitation totals are changing across the region are available here.

 in.cm.%
Annual total precipitation13.033.042.90
Winter total precipitation4.010.269.70
Spring total precipitation2.97.434.90
Summer total precipitation2.97.330.90
Fall total precipitation2.97.441.90

Heavy Precipitation

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