The year 2012 was the warmest on record in the contiguous United States, marked by extreme weather conditions including drought, hurricane, wildfires and storms, according to a report by the National Oceanic and Atmospheric Administration (NOAA).

The average temperature last year was 55.3°F, which was 3.2°F above the average temperatures in the 20th century and 1.0°F above the previous record set in 1998. Last year was also the second most extreme year on record for the country, next only to the year 1998.

The report indicated that every state in the contiguous U.S. (lower 48 states that exclude Alaska and Hawaii) had an above-average annual temperature in 2012. The lower 48 states experienced a record warm spring, second warmest summer, fourth warmest winter and a warmer-than-average autumn.

Nineteen of the states had a record warm year and an additional 26 states experienced one of the 10 warmest years in 2012.

As many as 11 disasters were witnessed in 2012 including Sandy and Isaac, which caused huge losses to the nation. Researchers point out that the report shows evidence of human activities, such as burning of fossil fuels, contributing to changes in the climate of the U.S., The Washington Post reports.

With the rise in temperatures, the country could expect to see extreme events in the future, according to Deke Arndt, chief of the climate monitoring branch, NOAA's National Climatic Data Center.

"We expect to see a continued trend of big heat events, we expect to see big rain events, and with slightly less confidence, we expect to see continued trend in drought," Arndt told the Los Angeles Times.

"This is consistent with what we would expect in a warming world."

Meanwhile, lower temperatures prevailed in Alaska last year. The state experienced cooler and slightly wetter than average temperatures in 2012.

The report, released Tuesday, did not mention about average global temperatures. According to the Los Angeles Times, the report, which will be released soon, is expected to show that 2012 was the eighth warmest year on record across the globe.