What date marks the longest day of the year in the Northern Hemisphere?

• A. June 21
• B. June 1
• C. July 4
• D. July 21

Answer: (A)

The date that marks the longest day of the year in the Northern Hemisphere is June 21. This day is known as the summer solstice, which occurs when the North Pole is tilted closest to the sun. As a result, it experiences the most extended period of daylight and the shortest night of the year. The phenomenon is significant in various cultures, often celebrated as the peak of summer.

The other dates provided do not correspond to the astronomical event that determines the longest day. June 1 is simply the beginning of June and does not have significance in relation to daylight duration. July 4, while notable for other reasons, does not mark an astronomical milestone, as the days after the summer solstice gradually begin to shorten. July 21, similarly, does not hold any astronomical relevance for the longest day, as the daylight hours continue to decrease post-solstice. Thus, June 21 stands out as the pivotal date for the longest day in the Northern Hemisphere.