After looking at the national ranking (23rd coldest) it is time to look at the State data:

In the last 119 Aprils, it was the coldest April ever in North Dakota. 2nd coldest ever in South Dakota. 3rd coldest ever in Minnesota, 4th coldest ever in Nebraska, 7th coldest ever in Oklahoma, 8th coldest ever in Wisconsin.

North Dakota was 18.5F colder than the warmest April (which occurred in 1915).

26 out of 48 states had an April ranked below 60. Which means they were ranked in the bottom half of the 119 Aprils measured by the NOAA.

Only one state (California) had an April in the top 20.

State	Apr 2013 Avg F	Apr Rank (1=Coldest)	Coldest Apr	Coldest Apr F
North Dakota	31	1	2013	31
South Dakota	36.7	2	1920	35.6
Minnesota	33.9	3	1950	32.5
Nebraska	42.3	4	1920	38.9
Oklahoma	54.6	5	1983	53.2
Kansas	48.3	7	1983	46.9
Wisconsin	37.6	8	1950	35.2
Montana	37.7	11	1975	33.7
Wyoming	35.8	12	1920	32.2
Iowa	43.7	13	1907	40.1
Michigan	39.1	16	1907	35
Arkansas	58.4	18	1907	54.1
Missouri	51.8	19	1907	47.6
Texas	63.1	20	1997	59.7
Colorado	40.4	21	1920	34.3
Louisiana	64.5	23	1983	61.4
Illinois	49.8	29	1907	43.2
Mississippi	62.2	35	1983	58.4
Tennessee	56.9	42	1907	50.6
Utah	45.6	44	1975	39.9
Alabama	62.1	48	1901	57.4
Washington	46.7	50	1955	41.5
Idaho	42.5	52	1975	36.5
Indiana	50.7	53	1907	42.2
Kentucky	54.9	53	1907	46.9
Georgia	63.1	57	1901	57.4
New York	43.5	59	1943	36.8
Maine	39.3	60	1926	33.2
South Carolina	62.1	60	1901	55.1
Oregon	46.3	61	1975	40.1
Oregon	46.3	61	1967	40.1
North Carolina	58.5	63	1907	51
Vermont	41.9	66	1926	33.3
Connecticut	47	68	1943	40
New Mexico	52.3	68	1973	45.8
Ohio	50.4	71	1907	41.3
Massachusetts	46.2	75	1943	40.3
Rhode Island	47.1	79	1907	40.9
Nevada	48.5	80	1967	38.6
Pennsylvania	49	80	1943	41.6
Maryland	53.7	82	1907	45.9
New Jersey	51.5	83	1907	44.5
West Virginia	52.9	83	1907	44.4
New Hampshire	43.3	87	1926	34.6
Arizona	59.7	89	1975	50.6
Virginia	56.2	89	1907	47.1
Delaware	54.5	90	1907	46.4
Florida	71.4	97	1987	65.1
Florida	71.4	97	1901	65.1
California	59.9	108	1967	46.5