The solar term corresponding to the longest day in the northern hemisphere is long summer B, summer solstice C and autumn equinox.

The solar term corresponding to the longest day in the northern hemisphere is long summer B, summer solstice C and autumn equinox.

The longest day of the year in the northern hemisphere is the summer solstice. On this day, the sun shines almost directly on the Tropic of Cancer, which is the highest latitude that solar energy reaches in the northern hemisphere in a year. The sun runs to 90 degrees of the Yellow Meridian (summer solstice), and the direct ground position is almost direct to the Tropic of Cancer, and the daylight time in all parts of the northern hemisphere reaches the longest in the whole year.

Summer solstice