September Equinox 2026: Why Nights Get Longer in India
The September equinox will occur on September 23 at 5:35 am IST, after which daylight gradually decreases and nights become longer across India.
The September equinox will occur on September 23 at 5:35 am IST, marking the astronomical transition from summer to autumn in the Northern Hemisphere. At this moment, the Sun crosses Earth’s equatorial plane as it moves from north to south.
An equinox occurs twice a year, in March and September, when neither hemisphere is tilted more towards the Sun. While the event is commonly associated with equal day and night, most locations do not experience exactly 12 hours of daylight and darkness.
India will also experience the September equinox. In New Delhi, for example, daylight on September 23 will last roughly 12 hours and seven minutes. The difference occurs because sunrise and sunset are affected by the Sun’s apparent size and Earth’s atmosphere, which bends sunlight near the horizon.
The equinox marks a turning point in the Sun’s apparent movement across the sky. After September 23, the Sun’s direct rays gradually shift farther south of the equator. For India and the rest of the Northern Hemisphere, daylight hours will gradually decrease while nights become longer as the year moves towards the December solstice.
Although the equinox itself is a precise astronomical moment, its effect on daylight unfolds gradually over the following weeks. So yes, longer nights are coming—but Earth isn’t suddenly switching to “winter mode” overnight.
