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When is First Day of Summer 2027?
First Day of Summer 2027 is on Monday, June 21, 2027 — that's 260 days (37 weeks) from today.
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First Day of Summer
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First Day of Summer 2027 Dates & Schedule
| Date | Monday, June 21, 2027 |
|---|---|
| Day of week | Monday |
| Countdown | 260 days (37 weeks) |
First Day of Summer 2027 is on Monday, June 21, 2027. That is 260 days away — about 37 weeks and 1 day, or roughly 8 months, from today. First Day of Summer is an astronomical season that begins at a solstice or equinox, the precise moment Earth's tilt reaches a turning point.
Use the date above to set a reminder or calendar entry. If First Day of Summer has an official organizer or observing authority, check its latest information before making bookings because times, venues, and local observance details can change. You can also add a free Outside countdown widget to your iPhone home screen; it updates every day and can be shared with other people.
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Open page →About First Day of Summer
The first day of Summer 2027 is Monday, June 21st.
History & Significance
This date marks the Summer Solstice in the Northern Hemisphere, the longest day of the year.
The Science Behind First Day of Summer
Seasons are driven by the tilt of Earth's axis — roughly 23.5 degrees — not by how close the planet is to the Sun. As Earth orbits, each hemisphere leans toward or away from the Sun, changing the angle of sunlight and the length of the day. The astronomical start of a season is pinned to a solstice or an equinox, the precise moment that geometry reaches a turning point.
That is why the start of First Day of Summer 2027 lands on a specific date and even a specific time, rather than the first of a month. Equinoxes bring near-equal day and night worldwide; solstices mark the longest or shortest day of the year. Knowing the exact changeover is useful for gardeners, photographers, and anyone tracking daylight hours.
First Day of Summer 2027: Frequently Asked Questions
When is First Day of Summer 2027?
First Day of Summer 2027 is on Monday, June 21, 2027 — 260 days from today. You can track it with a free countdown widget on your iPhone home screen using the Outside app.
What day of the week is First Day of Summer 2027?
First Day of Summer 2027 falls on a Monday. Knowing the weekday helps you plan time off, travel, or weekend activities around the date.
How long until First Day of Summer 2027?
First Day of Summer 2027 is 37 weeks away — roughly 9 months from now. That's plenty of time to plan ahead.
Is there a free First Day of Summer countdown app?
Yes. Outside is a free iPhone app with a First Day of Summer countdown widget for your home screen. Countdowns and standard widgets are free. Features such as custom reminders and calendar sync may require Outside Pro.
What causes First Day of Summer to begin?
First Day of Summer begins because of the 23.5-degree tilt of Earth's axis. As the planet orbits the Sun, each hemisphere leans toward or away from it, changing sunlight and day length. The season's astronomical start is pinned to a solstice or equinox.
Is the start of First Day of Summer the same date every year?
Not exactly. Because the solstice and equinox follow Earth's orbit rather than the calendar, the start of First Day of Summer can shift by a day or two from year to year. 2027 has its own precise changeover date and time.
What is the difference between meteorological and astronomical First Day of Summer?
Meteorological seasons are fixed three-month blocks used by forecasters, while astronomical seasons are defined by solstices and equinoxes. The date counted here is the astronomical start of First Day of Summer 2027.
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