While July 4 is usually hot for much of the U.S., the entire globe was toastier than usual on Tuesday. Monday and Tuesday were the two hottest days on record since at least 1979, according to data from the U.S. National Centers for Environmental Prediction.

So how hot was it Monday and Tuesday? July 4, 2023 was the hottest day on Earth since records began in 1979. The average global temperature reached 17.18 degrees Celsius (62.92 degrees Fahrenheit) Tuesday, surpassing the previous record of 17.01 degrees Celsius (62.62 degrees Fahrenheit) set on Monday, July 3, 2023. The previous record was 16.92 degrees Celsius (62.46 degrees Fahrenheit) set on August 14, 2016.

It's important to note that the hottest day on Earth is not the same as the hottest temperature ever recorded on Earth. The hottest temperature ever recorded on Earth was 134 degrees Fahrenheit (56.7 degrees Celsius), which occurred in Death Valley, California in 1913. While it was record-breaking heat in Death Valley, the average global temperature was much cooler on that day.

The average global daily temperature is compiled using data from the U.S. National Centers for Environmental Prediction and the University of Maine. This specific data set goes back to 1979, when satellite temperature monitoring began. Monday marked the first day that global temperatures averaged above 17 degrees Celsius.

These abnormally warm global temperatures are due to the combination of human-induced climate change and El Niño. El Niño is a natural climate pattern that causes the Pacific Ocean to warm, which in turn leads to warmer temperatures around the world.

While Monday and Tuesday were record-breaking, it's possible to see even warmer global average temperatures as we head into the remainder of the summer months in the Northern Hemisphere.