First Day Of Summer 2024 Time. Here's everything you need to know about the northern hemisphere's longest day of the year. When does summer start in 2024.
Thursday, june 20 is the official first day of northern astronomical summer for 2024 — summer solstice — which is the longest day of the year for this half of the planet. 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.