The solstice occurs when the Sun is closer to one of the hemispheres, causing one part of the world to have a larger day, while the other side has a smaller day. At the equinox, the Sun is closer to the Equator, so day and night in both hemispheres have the same duration.
The solstice happens twice a year, as does the equinox, and they mark the entrance of the new seasons. The solstice happens during summer and winter, while the equinox happens in the beginning of spring and autumn.
| Solstice | Equinox | |
| Position of the Sun | The Sun is at its furthest point from the equator. | The Sun is at the closest point to the equator. |
| Sun rays | The Earth receives a greater amount of light over one hemisphere. | The sun’s rays reach the intertropical zone with more intensity, making light and heat reach both hemispheres in the same way. |
| Date | · June 21 (winter solstice in the southern hemisphere and summer solstice in the northern hemisphere);
· December 21 (summer solstice in the southern hemisphere and winter in the northern hemisphere). |
· March 20 (spring equinox in the northern hemisphere and autumn in the southern hemisphere);
· September 23 (autumn equinox in the northern hemisphere and spring in the south). |
| Day length | Midsummer: longer day. Winter solstice: longer night. |
Day and night have the same duration during an equinox. |
| Meaning | From the Latin “sol” and “sistere”, which mean “Sol” and “stay still”. | From the Latin “aequus” and “nox”, which mean “equal” and “night”. |
Both the equinox and the solstice happen twice a year, and mark the entrance of the seasons. The sunny days are longer during the summer solstice, while the nights are longer during the winter solstice. The equinox happens during the beginning of autumn and spring, when the sun is closest to the equator.
An equinox happens at a specific time in time, the solstice happens for days.
These phenomena occur because the Earth has an elliptical path, and its tilted axis causes sunlight to reach the planet’s surface at different angles during its rotation.
What is the solstice?
“Solstice” comes from the Latin words sol and sistere , which mean “sun” and “stay still”. During the solstice, the Sun is closer to one of the hemispheres, making the day last longer, while the night is longer in the other hemisphere.
In the southern hemisphere, the winter solstice usually occurs on June 21. It is when the southern hemisphere is away from the sun and the northern hemisphere is tilted towards it. On December 21, there is the summer solstice in the southern hemisphere, and the winter solstice in the northern hemisphere.
What is the equinox?
The equinox occurs when the Sun is positioned exactly above a point on the equator, causing light and heat to be distributed in a similar way across the two hemispheres. In this way, day and night have the same duration.
On March 20, the equinox marks the beginning of spring in the northern hemisphere and autumn in the southern hemisphere. The September 22 equinox marks the beginning of autumn in the northern hemisphere and spring in the southern hemisphere.
Upcoming Solstices and Equinoxes
| Equinox | Solstice | Equinox | Solstice | |
| 2019 | 3/20 – 9:58 pm | 6/21 – 3:54 pm | 09/23 – 07:50 | 12/22 – 4:19 am |
| 2020 | 03/20 – 03:50 | 6/20 – 9:44 pm | 09/22 – 13:31 | 12/21 -10: 02 |
| 2021 | 03/20 – 09:37 | 06/21 – 00:32 | 9/22 – 7:21 pm | 12/21 -12: 59 |
