This year July 3, was the hottest day ever recorded globally, according to data from the US National Centers for Environmental Prediction.
The world's average temperature reached a new high on Monday, topping 17 degrees Celsius for the first time.
The US researchers said the new record was the highest in any instrumental record dating back to the end of the 19th century.
Scientists say a combination of a natural weather event known as El Niño and the ongoing emissions of carbon dioxide are driving the heat.
Earlier, it was also confirmed that this year’s June was the warmest ever recorded in history.
Scientists believe that the world's average temperature had reached 17.01C on 3 July, breaking the previous record of 16.92C that had stood since August 2016.
The scientists have been concerned about rising temperatures on land and at sea, since the beginning of this year.
There has been record spring heat in Spain and many countries in Asia witnessed marine heatwaves in places that don't normally see them, such as the North Sea.
China this week continued to experience an enduring heatwave with temperatures in some places above 35C, while the southern US has also been subject to stifling conditions.
Monday's high is the warmest since satellite monitoring records began in 1979. Experts also believe it is the highest since widespread instrumental records began towards the end of the 19th century.
How is combination of El Nino and carbon emissions causing heatwave?
The El Niño Southern Oscillation, or ENSO, as it is properly called, has three different phases: Hot, cold or neutral. It is the most powerful fluctuation in the climate system anywhere on Earth.
"The average global surface air temperature reaching 17C for the first time since we have reliable records available is a significant symbolic milestone in our warming world," said Leon Simons, a scientist was quoted by BBC as having said.
"Now that the warmer phase of El Niño is starting we can expect a lot more daily, monthly and annual records breaking in the next 1.5 years," he was quoted as having said.
Monday's record temperature comes as the month of June was confirmed as the hottest June in the global record. Average temperatures across the planet were 1.46C above the average in the period between 1850 and 1900.
England also recorded its hottest June while the impact of high temperatures is also being felt at the world's extremes.
In Antarctica, the July temperature record was broken with a reading of 8.7C taken at Ukraine's Vernadsky Research base.
Scientists believe that more records will be shattered as the summer goes on and El Niño gains strength.
"Chances are that July will be the warmest ever, and with it the hottest month ever: 'ever' meaning since the Eemian which is some 120,000 years ago," said Karsten Haustein, from the University of Leipzig, as per BBC report.
"While Southern Hemisphere temperatures will drop a bit in the next few days, chances are that July and August will see even warmer days yet given that El Niño is now pretty much in full swing,” he added.