"Nearly 100 thermal images of Neptune taken showed that its average global temperature plummet by a staggering 14 degrees Fahrenheit between 2003 and 2018"
"In Neptunes southern summer, we expected temperatures to be slowly growing warmer, not colder"
Astronomers observing Neptune for the past 17 years with multiple ground-based telescopes tracked a surprising drop in the ice giant's global temperatures, which was then followed by a dramatic warming trend at the planet's south pole.
One year on Neptune lasts for about 165 Earth years, so a single season can last around 40 years. It's been summertime in Neptune's southern hemisphere since 2005