WASHINGTON - Call it spring’s fever. Federal records show the United States just finished its hottest spring on record.

March, April, and May in the Lower 48 beat the oldest spring temperature record by a full 2 degrees.

The three months averaged 57.1 degrees, more than 5 degrees above average. That’s the most above normal for any US season on record.

The National Oceanic and Atmospheric Administration also reported Thursday that it was the second warmest May since records began in 1895. May averaged 64.3 degrees, just behind 1934.

The first five months of 2012 were the hottest start to a year in US weather record history. The 12-month period starting last June is also the hottest on record.

Meteorologists cited a persistent weather pattern.