The statement from NOAA is simple enough;
“The average May temperature across the contiguous U.S. was 65.4 degrees F, 5.2 degrees above average, making it the warmest May in the 124-year record, according to scientists at NOAA’s National Centers for Environmental Information.”
So, yes. If it felt warm, or maybe even a little hot, that’s because it was. Temperatures are climbing. Climates are changing. There’s no reason to expect those trends to stop.