March 2011 Weather Summary for Central and Southeast Illinois

March began its transition toward spring with several periods of above and below normal weather, which averaged out to be within a couple degrees of normal (left image below).  Precipitation was largely below normal, especially north of the I-72 corridor (right image below).  (Click images to enlarge.)

March average temperature departure from normal
Temperature departure from normal for March

Precipitation percentage of normal for March

A strong storm system affected much of the area on the 4th and 5th, producing a large amount of the observed precipitation for the month.  Rainfall totals of over an inch were widespead from the Illinois River southeastward, with the heaviest totals generally along and south of I-70.  An area of 2 to 2.5 inches occurred near the Illinois/Indiana border from Casey to Hutsonville, and 2.13 inches was also reported in west central Illinois near Winchester.  These rainfall totals caused minor flooding on some area rivers.

A substantial period of warmer weather prevailed from the 15-23rd, as astronomical spring approached.  Several days during this period featured temperatures well into the 70s, and were near 80 degrees in a few areas, especially south of I-70 and in west central Illinois west of Jacksonville.  On the warmest days, low temperatures were warmer than the normal highs.  The last several days of the month featured temperatures below normal, as high pressure near the Minnesota/Canada border kept Illinois in a perisistent northeast wind flow.

March's transition toward spring was interrupted by several periods of light snow and flurries during the last week of the month.  Snowfall of 1 to 3 inches fell south of the I-70 corridor on the 26th, primarily from Lawrenceville westward; this same system produced 4 inches or more from the St. Louis metropolitan area westward.

Some climate statistics for area cities:


Average temperature

Highest and
Lowest Temperatures




38.0 degrees

72 (22nd); 14 (1st)

1.99 inches 

0.3 inches 


41.5 degrees

73 (17th, 23rd); 23 (1st)

1.36 inches 

0.2 inches 


44.8 degrees

77 (21st); 25 (1st)

2.82 inches 



40.8 degrees

71 (20th); 23 (1st)

1.85 inches 



43.2 degrees

79 (21st); 22 (1st)

3.56 inches 



38.4 degrees

75 (20th); 20 (27th, 28th)

0.92 inches 

Not available 


41.3 degrees

73 (20th); 22 (28th )

1.40 inches



41.8 degrees

74 (22nd); 21 (1st) 

1.52 inches



43.4 degrees

76 (17th); 24 (1st, 27th)

1.60 inches


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