When exactly is the summer solstice?

The Northern Hemisphere summer solstice falls on June 20 or 21 each year (occasionally June 22 in rare years). The precise UTC minute varies annually as the Earth's orbit is not perfectly uniform. This tool uses a close astronomical approximation accurate to within a few minutes.

Is this tool accurate to the minute?

The solstice time is computed from a well-known simplified formula (based on Jean Meeus's "Astronomical Algorithms"). It is accurate to within roughly 2–5 minutes of the official computed solstice time published by observatories.

Does this tool account for my time zone?

The solstice moment is stored in UTC. The countdown subtracts the current UTC time from that target, so the result is independent of your local time zone — it is the same number of seconds for everyone on Earth simultaneously.

What if the summer solstice just passed?

The tool detects when the current year's solstice has passed and automatically switches the target to the following year's solstice so the countdown is always meaningful.

What about the Southern Hemisphere?

This tool targets the Northern Hemisphere summer solstice (June 20–21). For the Southern Hemisphere, the summer solstice occurs in December — that is a different date entirely.

Days Until Summer Solstice

See exactly how many days, hours, minutes, and seconds remain until the next Northern Hemisphere summer solstice.

Northern Hemisphere Summer Solstice Countdown

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Winter solstice 0% Summer solstice

Solstice Details

Target date: —
Approximate UTC time: —
Day of week: —
Total seconds remaining: —

What Is the Summer Solstice?

Longest day of the year in the Northern Hemisphere
Sun reaches its highest arc in the sky all year
Marks the astronomical start of summer
Occurs when Earth's axial tilt faces most toward the Sun
After this date, days gradually become shorter

Summary

The Northern Hemisphere summer solstice is the longest day of the year, occurring on or around June 20–21 when the Sun reaches its northernmost point above the equator. This tool calculates the precise astronomical solstice moment for the current or next year and counts down to it in real time. All computation is done in your browser using standard JavaScript date math — no server round-trips required.

How it works

The tool determines the approximate solstice date for the current year (June 20 or 21, computed via a simplified astronomical formula).
It compares that UTC datetime to the current local time in your browser.
If the solstice has already passed this year, it automatically targets next year's solstice.
A live ticker updates the remaining days, hours, minutes, and seconds every second.
When the moment arrives, the countdown shows a celebratory message.

Use cases

Find out how many days are left until the official first day of summer.
Plan a summer solstice celebration, festival, or outdoor event.
Track the solstice for astronomical observation or photography.
Settle a friendly debate about exactly when summer starts.
Use as a seasonal milestone for business planning or marketing campaigns.
Display on a dashboard alongside other date-countdown tools.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu