On December 21, 2025, countries across the Northern Hemisphere, including Bangladesh, experienced the longest night and shortest day of the year, marking the winter solstice. The astronomical event occurs when the Northern Hemisphere tilts farthest from the Sun, resulting in reduced daylight hours and the official onset of winter.

Scientists explain that Earth’s axial tilt causes seasonal variations as the planet orbits the Sun. Around June 21, the Northern Hemisphere leans toward the Sun, creating the longest day, known as the summer solstice. Conversely, in December, the Southern Hemisphere tilts sunward, bringing summer to the south and winter to the north.

The winter solstice has cultural and scientific significance, symbolizing renewal and the gradual lengthening of days ahead. Meteorological departments in South Asia noted cooler temperatures and longer nights, though no severe cold wave was reported. The event also serves as a reminder of Earth’s dynamic relationship with the Sun and its impact on global climate patterns.