The planet saw its hottest day ever this week. The record will be broken again and again

This week saw the hottest global temperature ever recorded, according to data from two climate tracking agencies.

On Monday, the average global temperature reached 17.01 degrees Celsius (62.62 Fahrenheit), the highest in the US National Centers for Environmental Prediction's data, which goes back to 1979. On Tuesday, it climbed even further, reaching 17.18 degrees Celsius. The previous record of 16.92 degrees Celsius was set in August 2016.

The European Union's Copernicus Climate Change Service on Wednesday also tweeted that Monday's global temperature was a record in its data set.

Experts warn that the record could be broken several more times this year. Robert Rohde, lead scientist at Berkeley Earth, said in a Twitter post on Tuesday that the world "may well see a few even warmer days over the next 6 weeks."

This global record is a preliminary one, but it's another indication of how fast the world is heating up, as the arrival of the natural climate phenomenon El Niño, which has a warming effect, is layered on top of climate change-fueled global heating.

"It's not a record to celebrate and it won't be a record for long, with northern hemisphere summer still mostly ahead and El Niño developing," said Friederike Otto, senior lecturer in climate science at the Grantham Institute for Climate Change and the Environment in the UK.

This year has already seen heat records broken around the world, with devastating consequences.

In the US, Texas and the South sweltered in a brutal heat wave in late June, with triple-digit-Fahrenheit temperatures and extreme humidity. Soaring temperatures in Mexico have killed at least 112 people since March.

A searing heat wave in India killed at least 44 people across the state of Bihar. China, too, has experienced several blistering heat waves and it registered the highest number of hot days - where the maximum daily temperature exceeded 35 degrees Celsius (95 degrees Fahrenheit) - over a six-month period since records began.

The UK recorded the hottest June since records began in 1884, according to the country's national weather service, the Met Office. The average temperature for the month was 15.8 degrees Celsius (60.4 Fahrenheit), breaking the previous record by 0.9 degree Celsius.

"Alongside natural variability, the background warming of the Earth's atmosphere due to human induced climate change has driven up the possibility of reaching record high temperatures," Paul Davies, Met Office climate extremes principal fellow and chief meteorologist, said in a statement.

As the climate crisis intensifies, scientists are clear that record-breaking heat waves are set to become more frequent and more severe.

The new global average temperature record is another wake-up call, Otto told CNN. "It just shows we have to stop burning fossil fuels, not in decades, now. This day is just a number, but for many people and ecosystems it's a loss of life and livelihood."