When Does Summer Start 2024 Canada. 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. In 2024, summer solstice in the northern hemisphere will occur on thursday, june 20 around 4:50 p.m.

Fall starts at the moment when the sun is directly over the equator, going from north to south: 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.