First Day of Winter Calculator — Winter Solstice Date Finder

First Day of Winter 2025: When Does Winter Start?

The first day of winter, also known as the winter solstice, marks the astronomical beginning of the winter season and the shortest day of the year. In 2025, the winter solstice in the Northern Hemisphere falls on December 21, while the Southern Hemisphere experiences its winter solstice in June. Use our calculator above to find the exact date and time for any year between 2000 and 2040.

What Is the Winter Solstice?

The winter solstice is an astronomical event that occurs when the Sun reaches its lowest point in the sky at solar noon for the year. Earth's axial tilt of approximately 23.44 degrees is maximally inclined away from the Sun, resulting in the shortest period of daylight and the longest night of the year. The word "solstice" comes from Latin sol (sun) and sistere (to stand still), because for a few days around the solstice, the Sun appears to rise and set at nearly the same points on the horizon.

Astronomical vs Meteorological Winter

There are two ways to define the start of winter. Astronomical winter is based on the Earth's axial tilt and begins on the date of the winter solstice, which varies between December 20–22 in the Northern Hemisphere and June 20–22 in the Southern Hemisphere. Meteorological winter follows a fixed calendar and always starts on December 1 in the Northern Hemisphere and June 1 in the Southern Hemisphere, making it easier for weather record-keeping and climate comparisons.

When Is the Winter Solstice?

In the Northern Hemisphere, the winter solstice occurs around December 20, 21, or 22 each year. In the Southern Hemisphere, the winter solstice occurs around June 20, 21, or 22. The exact timing depends on the Earth's orbital position and can shift slightly due to leap years and other gravitational factors. Use our interactive tool above to see the precise UTC date and time for any year from 2000 to 2040.

Why Does the Date of the Solstice Change?

The date of the solstice varies because the Earth's orbit around the Sun takes approximately 365.25 days, while our calendar year is 365 days (with leap years adding an extra day every four years). This mismatch causes the solstice to shift by about 6 hours each year, with leap years resetting the cycle. Additionally, gravitational perturbations from other planets slightly affect Earth's orbit, introducing minor variations in solstice timing.

Traditions and Celebrations Around the Winter Solstice

Many cultures celebrate the winter solstice with festivals and traditions. Yule, the ancient Germanic and Scandinavian festival, involved burning the Yule log and feasting to celebrate the rebirth of the Sun. In East Asia, the Dongzhi Festival is celebrated with family gatherings and traditional foods. Modern celebrations include holiday lights, gift-giving, and gathering with loved ones during the darkest time of the year.

Related Seasonal Tools

Interested in the other seasonal transitions? Check out our First Day of Spring, First Day of Summer, and First Day of Autumn calculators to find the exact dates of every equinox and solstice throughout the year.

Frequently Asked Questions

What is the exact date of the winter solstice in 2025?

In the Northern Hemisphere, the winter solstice in 2025 occurs on December 21. In the Southern Hemisphere, the winter solstice occurs in June 2025. Use the calculator above to see the exact UTC time for your selected year and hemisphere.

Is the first day of winter always December 21?

No, the winter solstice can occur on December 20, 21, or 22 in the Northern Hemisphere, depending on the year. The date varies due to the difference between the calendar year (365 days) and the astronomical year (approximately 365.25 days), as well as leap year cycles.

Why is the winter solstice the shortest day of the year?

The winter solstice is the shortest day of the year because Earth's axial tilt is maximally inclined away from the Sun in the respective hemisphere. This means the Sun follows its shortest path across the sky, resulting in the minimum amount of daylight hours. After the solstice, days gradually become longer.

Is the winter solstice the coldest day of the year?

Despite having the shortest day, the winter solstice is usually not the coldest day of the year. Due to "seasonal lag," oceans and land masses continue releasing stored heat for several weeks, so the coldest temperatures typically arrive 2 to 6 weeks after the solstice, in late January or early February in the Northern Hemisphere.

When does meteorological winter start?

Meteorological winter starts on December 1 in the Northern Hemisphere and June 1 in the Southern Hemisphere. This fixed-date system is used by meteorologists and climatologists to simplify seasonal record-keeping, as it aligns with the calendar months and allows for consistent comparisons of weather data across years.

How long does winter last?

Astronomical winter lasts approximately 88 to 89 days in the Northern Hemisphere (from the winter solstice to the spring equinox) and approximately 93 to 94 days in the Southern Hemisphere. The difference occurs because Earth moves faster in its orbit during January (near perihelion) than in July.

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First Day of Winter