August 2012 Central Indiana Climate Summary

 Central Indiana

August 2012

Climate Summary

43rd Warmest on record at Indianapolis

8th Wettest on record at Indianapolis



The previous pattern of hot days continued for the first several days in August, with temperatures in the 90s. Some locations even reached 100 degrees. Terre Haute reached 100 on August 2 and August 8. At Indianapolis, the high temperature of 98 degrees on August 8th tied the record for the date.

However, a big change occurred by the 10th, as a potent cold front brought below average temperatures to the area. Temperatures averaged normal or below normal for much of the period from August 10 to August 22. That period at Indianapolis was the longest stretch of normal or below normal average temperatures since February 2010. During this period, some locations in central Indiana saw low temperatures in the 40s.

The string of consecutive 80 degree or higher maximum temperatures at Indianapolis was broken on August 10, when the high only reached 77 degrees. The string of 64 days that began on June 7 is the second longest stretch of consecutive 80 degree or higher maximum temperatures for Indianapolis, second only to the 86 day stretch in 2002.

Normal to above normal temperatures returned for the last third of the month, with highs in the 80s and 90s.



August 2012   Avg Temp

August 2012 Difference from Normal

Highest Temperature

Lowest Temperature




98 on 8

54 on 18




98 on 4

49 on 18




92 on 3 and 8

47 on 18

Terre Haute



100 on 2 and 8

51 on 12 and 20




98 on 8

49 on 12




98 on 8

52 on 18 and 22

Indy – Eagle Crk.



97 on 2

54 on 18


At Indianapolis, there were 17 days with above normal average temperatures, 11 days with below normal average temperatures and 3 days with a normal average temperature.


August 2012 was the 43rd warmest in the Indianapolis area since 1871.




There was dramatic change in the rainfall pattern from July to August.  Some very dry areas of west central Indiana received over 10 inches of rainfall during August, while areas of south central Indiana that received over 8 inches in July turned much drier and received slightly over an inch of rainfall.   During August the big winners on the rainfall were many areas in the extreme to exceptional drought areas of west central and southwest Indiana.

The wet areas during August included much of central, northern and southwest Indiana.  Many locations in these areas received 3 to more than 8 inches of rainfall.  Extreme northern Indiana and most locations in south central and southeast Indiana missed out on most of this beneficial rainfall.  These areas received only 1 to 3 inches of rain for the month.  Normal rainfall for August is between 3 and 5 inches. 

Rain occurred numerous times during August, but areal coverage was never widespread.  There were four significant rain events in central Indiana.  Rain of 1 to 4 inches fell on the 4th-5th, 8th-9th, 16th-17th and the 27th.   The driest period during August was from 18th through 26th.  Little or no rain occurred in much of the state except during the evening of the 20th.  Isolated rains of up to an inch fell primarily north of I-70.

Drought conditions improved in most sections of central and northern Indiana and remained nearly the same or became worse in southern Indiana.   Although local area reservoirs remained below capacity, stream flow returned to normal in several areas of central Indiana, especially in the Indianapolis area.  Near to record low levels continued in the East Fork White River Basin of east central and southern Indiana. 



August 2012 Precipitation

August 2012 Difference from Normal

Wettest Day

Longest Dry Stretch




1.54 on 8-9

 9 days 18-26




2.49 on 26-27

 5 days 21-25




1.36 on 9-10

 5 days 22-26

Terre Haute



2.36 on 16-17

 4 days 22-25




1.87 on 16-17

 5 days 22-26




1.03 on 9

 6 days 21-26

Indy – Eagle Crk.



2.47 on 8-9

 5 days 21-25

    *- Precipitation data was not available on August 5 at Lafayette                       

August 2012 was the 8th wettest in the Indianapolis area since weather records began in 1871.


Severe Weather

The cold front that brought the return to cooler air to central Indiana also brought severe weather in the form of damaging winds and large hail on August 9.  Hail the diameter of billiard balls fell near Flora in Carroll County on August 9, and some buildings were damaged by winds in Carroll County as well.  More information on this event can be found at:

 Another cold front brought additional large hail, damaging winds, and heavy rain on August 16.

 For information on severe weather in other areas during August, visit the Storm Prediction Center “Severe Weather Event Summaries” website at



The maximum wind gust at Indianapolis International Airport was 44 mph out of the south on the 4th associated with a thunderstorm. Fog or haze was reported at Indianapolis on 11 days during the month.  Thunder was reported on 6 days during the month.


September 2012 Outlook

 The official outlook for September 2012 from the Climate Prediction Center indicates a greater chance of above normal temperatures for central Indiana.  At Indianapolis, the average temperature for the month is 66.9 degrees.  The outlook also calls for a greater chance of above normal precipitation. The average precipitation for September at Indianapolis is 3.12”.



Data prepared by the Indianapolis Forecast Office.

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