First Day Of Spring 2025 Dates Usa. When do the four seasons start in 2025—for spring, summer, fall, and winter? Ct, according to the farmer's almanac.

When is the longest day of the year in 2025? In the northern hemisphere, the astronomical start of spring, also known as the spring equinox, will occur on thursday, march 20, at 5:01 am edt in 2025.