The government reported Friday that the average temperature for the 48 contiguous United States from January through June was 51.8 degrees Fahrenheit — 3.4 degrees above average for the 20th century.
That made it the warmest such period since recordkeeping began in 1895, the National Climatic Data Center reported.
No state was cooler than average, and five states — Texas, Oklahoma, Kansas, Nebraska, and Missouri — experienced record warmth for the period.
While much of the Northeast experienced extreme rainfall and flooding at the end of June, many other areas continued to have below-normal rainfall and snowfall.
As of June, 45 percent of the contiguous U.S. was in moderate-to-extreme drought, an increase of 6 percent from May.
Dry conditions spawned more than 50,000 wildfires, burning more than 3 million acres in the continental U.S., according to the National Interagency Fire Center.
Worldwide, it was the sixth-warmest year-to-date since recordkeeping began in 1880.