Last month marked the Earth’s 400th consecutive month with above-average temperatures.

“We live in and share a world that is unequivocally, appreciably and consequentially warmer than just a few decades ago, and our world continues to warm,” said NOAA climate scientist Deke Arndt.

The combined ocean and land temperature was 1.49 degrees Fahrenheit (0.83 degrees Celsius) above the 20th century average of 56.7 degrees in April. That made last month the third-warmest April in records going back to 1880. The warmest year on record was 2016, followed by 2015, 2017 and 2014. December 1984 was the last month the planet had below-average temperatures.

Climate scientists use the 20th-century average as a benchmark for global temperature measurements. That’s because it’s fixed in time, allowing for consistent “goal posts” when reviewing climate data. It’s also a sufficiently long period to include several cycles of climate variability.

Carbon dioxide levels also hit another milestone, with the gas reaching its “highest level in recorded history at 410 parts per million” this past month.