Even higher temperatures are expected in July and August as El Niño strengthens.
For four days in a row, the planet reached its hottest day ever recorded as regions all over the world endure dangerous heat.
Earth warmed to the highest temperature ever recorded by human-made instruments when the average global temperature reached 17.18 degrees Celsius, or 62.92 degrees Fahrenheit, on Tuesday, as millions of Americans celebrated the Fourth of July, data from the U.S. National Centers for Environmental Prediction shows.
On Wednesday, the record was tied as global temperatures again reached 17.18 degrees Celsius. That record was broken on Thursday as global temperatures climbed to 17.23 degrees Celsius, or 63.01 degrees Fahrenheit, according to the NCEP.
The record was first set on Monday, when average global temperatures measured at 16.2 degrees Celsius, or 61.16 degrees Fahrenheit, but it only took one day to surpass that temperature.
The heat blanketing much of Earth has been driven by El Niño in combination with the greenhouse gas emissions responsible for global warming, researchers say.
Those conditions may prompt even hotter temperatures over the next six weeks, according to Robert Rohde, a physicist and lead scientist at Berkeley Earth, a non-profit environmental data analysis group.
Although the data only exists after 1979, this week's temperatures likely represent the record for long before global temperatures began to be recorded, Rhode said in a Twitter post on Wednesday.
"Global warming is leading us into an unfamiliar world," Rhode tweeted.
The record was broken at the same time that some regions in the southern United States are facing a weeks-long heat wave with dangerous temperatures, as well as intense heat domes occurring elsewhere in the world in places like China and North Africa.
Earth had the warmest June on record for air temperature and for sea surface temperature, but July and August could prove to be even hotter as El Niño continues to strengthen, Brian Brettschneider, a climate scientist based in Anchorage, Alaska, wrote on Twitter."
June global temperature has been climbing since 1980, Brettschneider said.
Heat is the number-one weather-related killer in the world, with more than 600 people dying from heat-related illnesses every year in the U.S., according to the Centers for Disease Control and Prevention.
At least 13 people have died from heat-related illness in Texas so far this summer.
ABC News' Max Golembo, Tracy Wholf, Samantha Wnek and Ginger Zee contributed to this report.