LOS ANGELES, July 5 (Xinhua) -- This week has seen the hottest global temperature ever recorded, according to data from the U.S. National Centers for Environmental Prediction (NCEP).

Tuesday was the hottest day on Earth since at least 1979, with the global average temperature reaching 62.92 degrees Fahrenheit (17.18 degrees Celsius), according to NCEP data.

Experts said that the record heat was driven by a series factors, including global warming, the return of the El Ni?o pattern and the start of summer in the northern hemisphere.

Dangerous levels of heat continue to hit the South, West and Midwest of the United States on Wednesday, according to data from the U.S. National Oceanic and Atmospheric Administration.

About 46.6 million people, 14 percent of the U.S. population, live in the areas expected to have dangerous levels of heat, according to a New York Times report.