| Season | Meteorological Dates (Northern Hemisphere) | |-------------|---------------------------------------------| | Spring | March 1 – May 31 | | Summer | June 1 – August 31 | | Autumn | September 1 – November 30 | | Winter | December 1 – February 28/29 |
1. Objective To define the relationship between calendar dates and astronomical seasons, accounting for hemispherical differences and the role of solstices and equinoxes. 2. Astronomical Basis of Seasons Seasons are caused by Earth’s axial tilt (approximately 23.5°) relative to its orbital plane around the Sun. As Earth orbits, different hemispheres receive more direct sunlight, creating seasonal changes. 3. Key Seasonal Markers (Astronomical Dates) The table below lists the astronomical start dates for each season in the Northern Hemisphere . Dates vary slightly (June 20–21, etc.) due to leap years and elliptical orbit. seasons and dates
| Season | Start Event | Typical Date Range (Northern Hemisphere) | |-------------|--------------------|-------------------------------------------| | Spring | Vernal Equinox | March 20 – 21 | | Summer | Summer Solstice | June 20 – 21 | | Autumn | Autumnal Equinox | September 22 – 23 | | Winter | Winter Solstice | December 21 – 22 | | Season | Meteorological Dates (Northern Hemisphere) |
