The average temperature of 51.1 degrees Fahrenheit broke the previous record set in 1910 by 0.5 degrees and was 8.6 degrees above average.
According to NOAA's preliminary data, more than 15,200 record high temperatures were set for March and all 50 states broke at least one record.
March wasn't the only month that brought the heat. The average temperature of the contiguous United States for the first three months of 2012 was six degrees above normal, NOAA announced.
The period from January through March for 2012 broke the previous first quarter record by 1.4 degrees. Weather records are normally beaten by tenths of a degree.
While the warm temperatures made winter more tolerable, it worried scientists.
"Everybody has this uneasy feeling. This is weird. This is not good," said Jerry Meehl, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo. "It's a guilty pleasure. You're out enjoying this nice March weather, but you know it's not a good thing."
The warm weather created favorable conditions for tornadoes and according to NOAA there were 223 preliminary tornado reports this March compared to an annual average of 80.
While individual events cannot be sited as examples of climate change, climate scientists said extreme temperatures and weather events will become more frequent as a result of man-made climate change.
Although North America experienced an abnormally warm winter, NOAA meteorologist Martin Hoerling said it is something the rest of the northern hemisphere did not.
Alaska's March ranked as its tenth coolest on record and its average first quarter temperature was its ninth coldest, 5.2 degrees below average.
The Associated Press contributed to this report.