Summer 2024 Start Date. When does summer start in 2024? Summer 2024 starts on thursday, june 20th in the northern hemisphere, with the first day of summer being the longest daylight day of the year with the earth's axis having reached its furthest tilt and begins to change directiion back.
Here’s everything you need to know about the northern hemisphere’s longest day of the year. When is first day of summer in 2024 is thursday, june 20, and it lasts until sunday, september 22, inclusive.