When Does The Summer Start 2024. Today (june 20) the summer solstice — the longest day of the year in the northern hemisphere — will begin, and it will be the earliest solstice in 228 years. When does summer start in 2024?

The summer solstice is nearly here, and we’re sharing all of the details about the first day of summer—take a look! The summer solstice marks the first day of summer.