The Associated Press: May the heat be with you _ another record month (AP) 16 hours ago WASHINGTON And the heat goes on: It was the warmest May on record. Worldwide, the average temperature for the month was 58.6 degrees Fahrenheit (14.8 Celsius), the warmest May on record, back to 1880. That was 1.24 degrees F (0.69 C) warmer than average for the month as the planet's temperature continues to climb. Atmospheric scientists generally attribute the rising readings to the greenhouse effect, with man-made chemicals added to the atmosphere trapping heat from the sun that previously would have gone back out into space. This year has also marked the warmest January-May period on record, according to the report from the National Climatic Data Center, an arm of the government's National Oceanic and Atmospheric Administration. Looking at just the United States, May temperatures were near average with cooler-than-normal temperatures in the West balanced by warmer-than-normal readings East.