When Does Summer Start 2025 Usa Dates. Click on the date that interests you to see the lighting map of the earth. Summer 2025 starts on friday, 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.

Find the answers to common questions, like: Here are the equinox and solstice dates—plus, answers to common questions about the seasons of the year in north america.