Autumn in Pakistan in 2024 begins on September 22.
The start of autumn in the Northern Hemisphere, which includes Pakistan, is marked by the September equinox. This celestial event occurs when the sun shines directly on the equator, and the Northern and Southern Hemispheres receive nearly equal amounts of sunlight.
According to data for Karachi, which serves as a representative location in Pakistan for seasonal timing based on astronomical events:
Key Equinox Dates for Karachi
The provided references (Time and Date: Solstices & Equinoxes for Karachi, Time and Date: Seasons in Karachi) indicate the following September equinox dates:
| Year | March Equinox | September Equinox |
|---|---|---|
| 2024 | Mar 20 | Sep 22 |
| 2025 | Mar 20 | Sep 22 |
| 2026 | Mar 20 | Sep 23 |
| 2027 | Mar 21 | Sep 23 |
As shown in the table, the September equinox in 2024 occurs on September 22. This date officially signifies the start of the astronomical autumn season in Pakistan and the rest of the Northern Hemisphere.
Understanding the Seasons
The change of seasons is primarily due to the Earth's axial tilt as it orbits the sun. The equinoxes (vernal in March and autumnal in September) and solstices (summer in June and winter in December) mark the transition points between these seasons.
- September Equinox: Marks the beginning of autumn in the Northern Hemisphere and spring in the Southern Hemisphere. Day and night are roughly equal in length across the globe.
- March Equinox: Marks the beginning of spring in the Northern Hemisphere and autumn in the Southern Hemisphere.
- June Solstice: Marks the beginning of summer in the Northern Hemisphere and winter in the Southern Hemisphere.
- December Solstice: Marks the beginning of winter in the Northern Hemisphere and summer in the Southern Hemisphere.
While the astronomical definition places the start of autumn on the September equinox, meteorological autumn typically begins on September 1st, based on average temperature cycles. However, the question specifically asks for the exact answer related to the astronomical event reflected in the reference data.
Therefore, using the astronomical definition based on the September equinox, autumn in Pakistan in 2024 starts on September 22.
