Q. In the northern hemisphere, the longest day of the year normally occurs in the : (UPSC Prelims 2022)
Answer:
Second half of the month of June
Notes: The correct answer is
[B] Second half of the month of June. This phenomenon is known as the
Summer Solstice in the Northern Hemisphere.
- Summer Solstice (Correct): The longest day of the year usually occurs on June 21 or 22. This falls squarely in the second half of June. On this day, the Northern Hemisphere is tilted at its maximum toward the Sun, and the Sun is directly overhead at the Tropic of Cancer (23.5° N latitude).
- Daylight Duration: During this period, all locations north of the equator experience their longest period of daylight and shortest night of the year. Locations within the Arctic Circle experience 24 hours of daylight (the "Midnight Sun").
- Seasonal Lag: While June 21/22 marks the peak of solar radiation, the hottest temperatures of summer usually arrive in July or August due to "seasonal lag," as the Earth's oceans and landmasses take time to absorb and release heat.
- Southern Hemisphere: Conversely, this same date marks the Winter Solstice for the Southern Hemisphere, representing their shortest day and longest night of the year.
The exact timing can shift slightly between June 20, 21, or 22 due to the tropical year (the time it takes for Earth to orbit the Sun) being approximately 365.242 days, which is accounted for by our leap year system.