National Weather Service United States Department of Commerce

Excessive Rainfall and Flooding Threat in the South; Hazardous Heat in the Western U.S. Expanding to the Northern Plains

Multiple rounds of heavy rain and thunderstorms across portions of the Texas and Louisiana Coast will likely lead to flash, urban, small stream and river flooding. An additional heavy rainfall threat will exist from the Lower Mississippi Valley through the southern Mid-Atlantic. Meanwhile, a dangerous heat threat will continue across the Western U.S. and northern Plains through Thursday. Read More >

Growing season is almost underway across the area and it's that time of year when crops/fruit trees/gardens and other vegetation could become susceptible to the possibility for frost and near freezing temperatures at night. Typically, frost can occur when the temperature falls below 36°F, especially in rural areas. It is a localized phenomena and can be quite variable across a small area. While the National Weather Service does not keep track of "frost" in observations per se, we do keep track of when temperatures hit the freezing mark or fall below. Frost becomes more widespread when the temperature falls below 32°F with some freeze possible. A hard freeze is possible when temperatures fall below 28°F. The maps below, courtesy of the Midwestern Regional Climate Center, show dates for various spring freeze parameters. Click on the images for a larger resolution or see additional maps here.

Spring Freeze 28 degrees Spring freeze 32 degrees
Median date of last 28 degree freeze Median date of last 32 degree freeze

 


Freeze Information for the Local Area

 

The tables below utilize data from the MRCC's Freeze Date Tool. Explore the tool here. Average dates below are county-based (noted in italics). Earliest and latest dates, along with the indicated period of record, are noted from the specific climate site (city noted in bold).

 

32° Freeze (at or below 32°F)

Location Average Last Date Earliest Late Date Latest Date Record Period

Benton Harbor

Berrien Co., MI

April 28 March 30 (1941) June 22 (1922)  1890-present

Defiance, OH

Defiance Co., OH

 April 25 April 13 (2011) May 12 (2009) 1998-present

Fort Wayne

Allen Co., IN

April 25

April 1 (1922)

May 27 (1961)

1912-present

Goshen, IN

Elkhart Co., IN

April 29 April 17 (2007) May 21 (2002) 1997-present

Lima, OH

Allen Co., OH

April 25 April 3 (2011) May 19 (2002) 1998-present

South Bend

St. Joseph Co., IN

April 29 April 7 (1984) May 29 (1897) 1893-present

 

 

28° Freeze (at or below 28°F)

Location Average Last Date Earliest Last Date Latest Date Record Period

Benton Harbor

Berrien Co., MI

April 13 March 17 (1929) May 28 (1992)  1890-present

Defiance, OH

Defiance Co., OH

 April 12 March 30 (1999) May 4 (2005) 1998-present

Fort Wayne

Allen Co., IN

April 12

March 10 (1929)

 May 13 (1946) 1912-present

Goshen, IN

Elkhart Co., IN

April 15 March 27 (2010) May 4 (2010) 1997-present

Lima, OH

Allen Co., OH

 April 10 March 18 (2005) April 26 (2006) 1998-present

South Bend

St. Joseph Co., IN

April 15 March 18 (1980) May 25 (1925) 1893-present

 


Modified Growing Degree Days (GDD) - Season and Month To Date

These maps will be updated with the start of growing season

Modified Growing Degree Days are similar to Growing Degree Days with several temperature adjustments. If the daily maximum temperature is above 86°F, it is reset to 86°F. If the daily minimum temperature is below 50°F, it is reset to 50°F. Once the max/min temperatures have been modified (if needed), the average temperature for the day is computed and compared with a base temperature, which is usually 50°F for corn and soybeans. Modified Growing Degree Days are typically used to monitor the development of corn, the assumption being that development is limited once the temperature exceeds 86°F or falls below 50°F. For example, if the high for the day was 92°F and the low 68°F, the average for use in the Modified GDD calculation would be 86 + 68 = 154 / 2 = 77. Click on the maps below to go to the most recent versions of the data from Midwestern Regional Climate Center.

 

Season to Date

 This map shows the total growing degree days since start of the growing season.  The start of the season is defined as April 1.

Month to Date

This map shows the total growing degree days since start of the month.

Total modified growing degree days since April 1st Total modified growing degree days since May 1st
 Total modified growing degree day departure since April 1st  Total modified growing degree day departure since May 1st

Month Departure from Normal

Season Departure from Normal

 

Updated 4/14/2024 -KB