Frost and Freeze Information
National Weather Service United States Department of Commerce

Overview

28F: Freeze Maps

32F: Freeze Maps

Earliest/Latest Freeze Date

NWS Products & Preparedness

 


 

Updated September 2022

Overview

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.  In the 32F/28F Freeze Maps section, you'll find national and regional maps from the Midwest Regional Climate Center (MRCC) that depict the typical dates for freezes in the early fall, and the earliest/latest freeze dates observed in the past. In the Earliest/Latest Freeze Dates section, you'll find statistics on the earliest and latest fall freeze dates for selected sites across our forecast area. In the preparation section, we have information about NWS Frost Advisories and Freeze/Hard Freeze Watches/Warnings, along with some tips for protecting plants. 

To view the latest forecast for your specific location, type in your zipcode in the green box on the upper left hand side of this screen that says, "Customize your weather.gov"

 

Climatology

 

When do we normally see our first 32°F freezes and 28ºF freezes? Check out these maps from the Midwest Regional Climate Center (MRCC) for freeze information on your location. Visit the link to the MRCC to view interactive maps where you can zoom in closer to your specific region.

 

Dates for 32°F Freezes

 

Median Dates for the First 32ºF Freezes

 

Fig. 1. Climatological Date of Median First 32°F freeze for the United States. 

 

Fig. 2. Climatological Date of Median First 32°F freeze for the region.

 

Earliest/Latest Dates for the First 32ºF Freezes

Below are images depicting the earliest and the latest dates for the first 32°F freezes across the U.S. and in our region. 

 

Fig. 3. Climatological Date of Earliest First 32°F freeze for the United States.

 

Fig. 4. Climatological Date of Earliest First 32°F freeze for the region.

 

Fig. 5. Climatological Date of Latest First 32°F freeze for the United States.

 

Fig. 6. Climatological Date of Latest First 32°F freeze for the region.

 

Dates for 28°F Freezes

 

Median Dates for the First 28ºF Freezes

 

Fig. 7. Climatological Date of the Median First 28°F freeze for the United States.

 

Fig. 8. Climatological Date of Median First 28°F freeze for the region.

 

Earliest/Latest Dates for the First 28ºF Freezes

Below are images depicting the earliest and the latest dates for the first 28°F freezes across the U.S. and in our region. 

 

Fig. 9. Climatological Date of the Earliest First 28°F freeze for the United States

 

Fig. 10. Climatological Date of the Earliest First 28°F freeze for the region.

 

Fig. 11. Climatological Date of the Latest First 28°F freeze for the United States.

 

Fig. 12. Climatological Date of the Latest First 28°F freeze for the region.

 

Earliest/Latest Freeze Dates for Select Sites

 

Earliest Dates for the First 32ºF Freezes

 

Site

Earliest Date

(Year)

2nd Earliest

(Year)

3rd Earliest

(Year)

4th Earliest

(Year)

5th Earliest

(Year)

Fort Wayne, IN Area

9-23

1995,1974,1967

9-24

1989,1950

9-25

1942

9-26

1928

9-27

1991

South Bend, IN Area

9-21

1897

9-23

1896

9-24

1928

9-25

1942

9-28

1991

Lima, OH WWTP

9-18

1959

9-19

1916

9-21

1962,1956

9-22

1918

9-23

1995,1974,1967,1947,1913

Coldwater, MI

9-07

1918

9-11

1943

9-17

1959

9-18

1900

9-19

1901

Marion, IN (2N)

9-14

2013,1902,1899

9-16

1916

9-18

1959

9-19

1901

9-21

1956,1897

Defiance,OH

9-18

1959,1903

9-20

1896

9-21

1962,1901,1897

9-23

1995,1974,1947

9-25

1942,1894

Benton Harbor,MI

9-13

2017,1985

9-17

1990

9-21

1991,1962

9-23

1992,1954,1947

9-24

1993,1989,1976,1950,1944

Goshen, IN (3W)

9-11

1917

9-18

1959,1916

9-19

1929

9-21

1962,1956

9-22

1918

 

Latest Dates for the First 32ºF Freezes

 

Site

 

Latest Date

(Year)

2nd Latest

(Year)

3rd Latest

(Year)

4th Latest

(Year)

5th Latest

(Year)

Fort Wayne, IN Area

11-24

1931

11-12

2016

11-10

1932

11-08

1938

11-06

1940

South Bend, IN Area

11-11

1985

11-07

1940,1902

11-05

1973

11-04

1971,1931

11-03

1998,1995

Lima, OH WWTP

11-12

2016

11-11

1932

11-07

2004,1994

11-04

1973,1971

11-03

1986

Coldwater, MI

10-29

1920

10-26

2017,2005,1941,1936

10-25

2016,1914

10-24

1949,1911

10-22

2013,2011,2010

Marion, IN (2N)

11-12

2016

11-08

1947

11-07

1940

11-04

1971,1943

11-03

1984,1919

Defiance, OH

11-20

1985

11-08

2004

11-04

1998,1971

11-02

1984

11-01

2010

Benton Harbor, MI

11-26

1890

11-25

1931

11-12

1940

11-10

1918

11-09

1938

Goshen, IN (3W)

11-04

1973

11-02

2007

11-01

1971

10-30

1963

10-29

1941

 

Earliest Dates for the First 28ºF Freezes

 

Sites

Earliest Date

(Year)

2nd Earliest

(Year)

3rd Earliest

(Year)

4th Earliest

(Year)

5th Earliest

(Year)

Fort Wayne, IN Area

10-1

1899

10-2

1908

10-03

1974

10-05

1965

10-06

1966

South Bend, IN Area

10-02

1908

10-03

1974

10-06

1952,1935

10-07

1964

10-08

1896

Lima, OH (WWTP)

9-26

1940

10-02

1974,1908

10-04

1935

10-05

1965

10-06

1966

Coldwater, MI

9-21

1897

9-28

1942

9-29

1951

9-30

1899

10-01

1939

Marion, IN

9-26

1928

9-28

1942

10-01

1899

10-02

2003,1958,1908

10-03

1974

Defiance, OH

9-21

1897

9-23

1896

10-01

1899

10-02

1974,1908,1895

10-03

1981

Benton Harbor, MI

9-24

1989

9-26

1947

9-28

1991

9-30

1984

10-02

1981

Goshen, IN

(3W)

9-28

1942

9-29

1951

10-01

1939,1918

10-03

1974

10-04

1989

 

Latest Dates for the First 28ºF Freezes

 
Sites

Latest Date

(Year)

2nd Latest

(Year)

3rd Latest

(Year)

4th Latest

(Year)

5th Latest

(Year)

Fort Wayne, IN Area

11-25

1931

11-24

1922

11-23

1918

11-20

1985,1929

11-16

1970,1924

South Bend, IN Area

11-26

1902

11-25

1931

11-23

1963

11-22

1994,1975

11-21

1922

Lima, OH (WWTP)

11-27

1902

11-23

2007

11-22

2015,1994

11-18

2011,1946

11-17

2005,2000,1999

Coldwater, MI

11-20

1985

11-11

2013,1994

11-09

2001

11-07

1958,1921

11-06

1927

Marion, IN

11-23

1994

11-20

1985

11-17

2005

11-16

1970

11-14

1975

Defiance, OH

11-23

2007,1994

11-21

1985

11-18

2000

11-12

2001,1932

11-09

2017,2004,1956,1943

Benton Harbor, MI

12-04

1899

12-02

1931

11-29

1923

11-28

1890

11-27

1912

Goshen, IN (3W)

11-23

2007

11-20

1985

11-15

2000,1975,1970

11-13

1992

11-12

2016,2013,2009,2004

Reviewed September 2022

 

Preparation

 

Do you know what products the National Weather Service issues about frost and freezes? Frost Advisories and Freeze Warnings can help you make decisions about what to do with temperature-sensitive plants at the beginning/near the end of the growing season. Once there is a hard freeze or killing freeze, these products are no longer issued.

 

Frost Advisory

Frost Advisories are only issued from May 1-October 20th (can be extended if necessary). A frost advisory is issued when temperatures, winds, and sky cover are favorable for frost development. This is most likely when temperatures are less than or equal to 36 degrees. Coverage of frost in these cases should be more than patchy. If a frost is sufficiently severe to end the growing season, it is commonly referred to as a 'killing frost.'

What to do: If a Frost Advisory is issued for your area, cover up plants before the sun sets so that it can help retain heat near the plants. 

 

Freeze Warning/Watch

Freeze Warnings are only issued from May 1-October 20th (can be extended if necessary). A freeze warning is issued when low temperatures are expected to be 29-32 degrees. A Freeze Watch may be issued a few days ahead of time if the potential exists for temperatures to fall into these thresholds.

What to do: If a Freeze Warning/Watch is issued for your area, there is little you can do to protect plants. If you can move your sensitive plants inside, do so because the freeze will likely kill them, depending on the severity of conditions.

 

Hard Freeze Warning/Watch

Hard Freeze Warnings are only issued from May 1-October 20th (can be extended if necessary). A hard freeze warning is issued when temperatures are expected to be 28 degrees or less.  A Hard Freeze Watch may be issued a few days ahead of time if the potential exists for temperatures to fall into these thresholds.

What to do: If a Hard Freeze Warning/Watch is issued for your area, there is little you can do to protect plants. If you can move your sensitive plants inside, do so because the freeze will kill them.