Temperatures in the United States are heating up fastest in the Northeast and the Southwest regions, an analysis of federal climate records reveals.

Northeastern states, with Maine and Vermont taking the lead, have grown the hottest in annual temperatures over the last 30 years, gaining an average of 2.5 degrees.

But Southwestern states as well have warmed the most during the typically hottest months; summer months in New Mexico are now 3.4 degrees warmer now than they were in 1984 and those lazy, crazy days are 2.8 degrees hotter in Texas.

The annual average temperature has warmed by 1.2 degrees since 1984 in the contiguous U.S., with summers specifically picking up 1.6 degrees annually.

Scientists explain some areas in the country have gotten hotter than others because of atmospheric factors and a level of climatic randomness.

"In the United States, it isn't warming equally," Kelly Redmond, climatologist at the Western Regional Climate Center in Reno, Nevada, told the Associated Press.

So, while people in the East and Midwest were complaining about how cold and snowy this last winter was, Nevada and California saw some of their warmest winter months ever recorded.

To find out what parts of the country have warmed the most, the AP examined National Climatic Data Center trends in the lower 48 states, 192 cities and 344 smaller regions within the states.

Climate researchers suggested using 1984 as a starting point because 30-year periods are commonly used as the accepted time frame in which to hold scientific studies.

Besides that, 1984 had an average temperature and was not a "cherry-picked" year to skew result of the analysis one way or another. The trend was calculated by the NCDC using the least squares regression method, which is a standard statistical tool.

All but one of the lower 48 states have warmed since 1984. North Dakota is the lone outlier, and cooled slightly.