Season Calculator
Find season for any date.
Input
Result
What is a Season Calculator?
A Season Calculator determines the current season and the dates of equinoxes and solstices for any given year. It uses astronomical data about Earth's orbit and axial tilt to calculate the exact moments when seasons change.
How to calculate seasons manually (the formula)
Seasons are determined by the Earth's axial tilt of 23.5°. The summer solstice occurs when the Northern Hemisphere is tilted most toward the sun (around June 21). The winter solstice occurs when it is tilted farthest away (around December 21). Equinoxes occur when the tilt is perpendicular to the sun (around March 20 and September 22), giving equal day and night.
Example calculation
For the year 2026: the March equinox occurs on March 20, the June solstice on June 21, the September equinox on September 23, and the December solstice on December 21. Spring runs from March 20 to June 21 in the Northern Hemisphere.
Common mistakes
- Assuming seasons start on the 1st of a month — Astronomical seasons start on equinoxes and solstices, which vary by date each year.
- Forgetting hemisphere differences — Summer in the Northern Hemisphere is winter in the Southern Hemisphere. Always select your hemisphere.
- Confusing meteorological and astronomical seasons — Meteorological seasons are fixed (Mar–May = spring), while astronomical seasons vary with Earth's orbit.
Frequently asked questions
How are seasons determined?
Seasons are based on the Earth's axial tilt and orbit around the sun.
What are equinoxes and solstices?
Equinoxes mark equal day and night; solstices mark longest and shortest days.
When is the spring equinox?
Around March 20th in the Northern Hemisphere.
When is the summer solstice?
Around June 21st in the Northern Hemisphere.
Does the calculator work for both hemispheres?
Yes, you can select Northern or Southern Hemisphere.
Is this free?
Yes, completely free.