First Day of Winter

Welcome to the First Day of Winter calculator. Find the exact date and time of the winter solstice — the astronomical start of winter and the shortest day of the year — for any year between 2000 and 2038. This tool includes a live countdown, complete seasonal timeline, daylight hours comparison across latitudes, multi-year comparison, and in-depth astronomical explanations. It supports both Northern Hemisphere (December solstice) and Southern Hemisphere (June solstice) calculations.

What Is the Winter Solstice?

The winter solstice (from Latin sol meaning "sun" and sistere meaning "to stand still") is the astronomical moment when the Sun reaches its lowest arc across the sky at solar noon. On this day, one hemisphere experiences its shortest period of daylight and longest night of the year. The Sun appears to "stand still" at its southernmost (or northernmost) point before reversing direction.

The winter solstice marks the beginning of astronomical winter. Paradoxically, it is also the turning point after which days begin to grow longer — a phenomenon celebrated by cultures worldwide for millennia as the "return of the light."

When Is the First Day of Winter?

The first day of winter (winter solstice) typically falls between December 20–22 (Northern Hemisphere) or June 20–22 (Southern Hemisphere). The exact date varies each year because Earth's orbital period is approximately 365.2422 days — not a perfect 365. This fractional difference, corrected by leap years, causes the solstice to shift by roughly 6 hours each year, then snap back during leap years.

Why the Date Changes

• Orbital fraction: Each year the solstice drifts later by about 5 hours 49 minutes relative to the calendar.
• Leap year correction: Adding February 29 shifts the solstice earlier by about 18 hours, keeping it anchored to December 20–22.
• Planetary perturbations: Gravitational pull from the Moon, Jupiter, and Venus create minor variations of a few minutes.

Astronomical Winter vs. Meteorological Winter

There are two ways to define the start of winter:

Meteorological seasons are preferred for climate statistics because they align better with temperature patterns and simplify data comparison. Astronomical seasons, however, are rooted in precise celestial mechanics and are used in this calculator.

Northern vs. Southern Hemisphere

The same astronomical event is experienced differently by each hemisphere:

Northern Hemisphere winter is shorter because Earth is near perihelion (closest to the Sun) during January, causing it to move faster through its orbit.

How to Use This Calculator

1. Select a year: Choose any year from 2000 to 2038 using the dropdown or the quick-access buttons.
2. Choose hemisphere: Northern Hemisphere uses the December solstice; Southern uses the June solstice as the start of winter.
3. View results: See the exact date, UTC time, live countdown (for future solstices), all four seasonal markers, winter duration, daylight hours at various latitudes, and a 5-year comparison.

Understanding Your Results

Live Countdown

For upcoming solstices, a real-time countdown shows days, hours, minutes, and seconds remaining until the exact moment of the winter solstice.

All Four Seasons

The seasonal timeline displays the year's four astronomical events (two equinoxes and two solstices), labeled appropriately for your chosen hemisphere. The winter solstice is highlighted for easy identification.

Daylight Hours by Latitude

See how the duration of daylight on the solstice varies dramatically by latitude — from barely 4 hours near the Arctic to nearly 12 hours near the equator. This visualization helps illustrate why the solstice has such different cultural significance across regions.

Season Duration

Winter's duration — from the winter solstice to the vernal equinox — varies between hemispheres. Northern winter lasts about 88–89 days, while southern winter lasts approximately 93–94 days, because Earth moves faster in its orbit near perihelion.

Multi-Year Comparison

The 5-year table shows how the solstice date and time shift across years, making it easy to spot the leap-year pattern and plan ahead.

Winter Solstice Traditions Around the World

Frequently Asked Questions

When is the first day of winter?

The first day of winter (winter solstice) occurs in December for the Northern Hemisphere (typically December 20–22) and in June for the Southern Hemisphere (typically June 20–22). The exact date and time vary each year because Earth's orbital period is approximately 365.2422 days. In 2026, the Northern Hemisphere winter solstice falls on December 21 at 20:50 UTC.

What happens during the winter solstice?

During the winter solstice, the Sun reaches its lowest point in the sky at solar noon and the Earth's axial tilt is farthest from the Sun in the respective hemisphere. This produces the shortest day and longest night of the year. After the winter solstice, days gradually become longer as the hemisphere begins tilting back toward the Sun.

Why does the first day of winter change each year?

The first day of winter varies because Earth's orbital period is approximately 365.2422 days, not exactly 365 days. This fractional difference, combined with the leap year cycle, causes the solstice to shift by about 6 hours each year, then jump back when a leap year adds an extra day. Gravitational perturbations from the Moon and other planets also create slight variations.

How long does winter last?

Astronomical winter (from the winter solstice to the vernal equinox) lasts approximately 88–89 days in the Northern Hemisphere. In the Southern Hemisphere, winter (June solstice to September equinox) lasts approximately 93–94 days. The difference occurs because Earth moves faster in its orbit during January than July.

What is the difference between astronomical winter and meteorological winter?

Astronomical winter begins at the winter solstice (around December 21 in the Northern Hemisphere) and is based on Earth's position relative to the Sun. Meteorological winter always starts on December 1 and is based on the annual temperature cycle, dividing the year into four 3-month seasons. Meteorological seasons are preferred for weather forecasting and climate statistics.

Is the winter solstice the coldest day of the year?

No, the winter solstice is usually not the coldest day. The coldest temperatures typically occur 2–6 weeks after the solstice due to "seasonal lag" — the delay between minimum solar heating and minimum temperatures. Oceans and land masses store heat and release it slowly, so it takes time for temperatures to reach their lowest point even after daylight begins increasing.

Additional Resources

• Winter Solstice — Wikipedia