Welcome to our Summer Solstice 2017 page! When does summer 2017 begin in the Northern Hemisphere? What is the solstice about—and why have people celebrated it throughout the ages?
When is the Summer Solstice 2017?
In 2017, the summer solstice falls on Wednesday, June 21, at 12:24 A.M. EDT.
Due to time zones, this means the solstice falls on Tuesday, June 20, in the rest of North America! For example, here are U.S. time zones:
- Wednesday, June 21, 12:24 A.M. EDT
- Tuesday, June 20, 11:24 P.M. CDT
- Tuesday, June 20, 10:24 P.M. MDT
- Tuesday, June 20, 9:24 P.M. PDT
Note: this is only the “summer” solstice in the Northern Hemisphere. (Our Almanac is published in North America.) It is the winter solstice in the Southern Hemisphere.
What is the Summer Solstice?
The timing of the solstice depends on when the Sun reaches its northernmost point from the equator.
The word solstice is from the Latin solstitium, from sol (sun) and stitium (to stop), reflecting the fact that the Sun appears to stop at this time (and again at the winter solstice).
In temperate regions, we notice that the Sun is higher in the sky throughout the day, and its rays strike Earth at a more direct angle, causing the efficient warming we call summer.
This summer solstice is the day with the most hours of sunlight during the whole year. See our handy sunrise and sunset calculator for how many hours of sunlight you get in your location.
At the winter solstice, just the opposite occurs: The Sun is at its southernmost point and is low in the sky. Its rays hit the Northern Hemisphere at an oblique angle, creating the feeble winter sunlight.
Why Doesn’t the Summer Solstice Fall on the Same Date Each Year?
The summer solstice in the Northern Hemisphere ranges in date from June 20 to 22. This occurs in part because of the difference between the Gregorian calendar system, which normally has 365 days, and the tropical year (how long it takes Earth to orbit the Sun once), which has about 365.242199 days. To compensate for the missing fraction of days, the Gregorian calendar adds a leap day about every 4 years, which makes the date for summer jump backward. However, the date also changes because of other influences, such as the gravitational pull from the Moon and planets, as well as the slight wobble in Earth’s rotation.
Did You Know?
Question: Why isn’t the summer solstice—the longest day of the year—also the hottest day of the year?
Answer: Earth’s atmosphere, land, and oceans absorb part of the incoming energy from the Sun and store it, releasing it back as heat at various rates. Water is slower to heat (or cool) than air or land. At the summer solstice, the Northern Hemisphere receives the most energy (highest intensity) from the Sun due to the angle of sunlight and day length. However, the land and oceans are still relatively cool, due to spring’s temperatures, so the maximum heating effect on air temperature is not felt just yet. Eventually, the land and, especially, oceans will release stored heat from the summer solstice back into the atmosphere. This usually results in the year’s hottest temperatures appearing in late July, August, or later, depending on latitude and other factors. This effect is called seasonal temperature lag.
Question: What is Midsummer Day (June 24)?
Answer: Around the time of the summer solstice, this day was the midpoint of the growing season, halfway between planting and harvest. Read more about the ancient Quarter Days!
Seasons on Other Planets
- Mercury has virtually no tilt (less than ⅓0th of a degree) relative to the plane of its orbit, and therefore does not experience true seasons.
- Uranus is tilted by almost 98 degrees and has seasons that last 21 years.
In Sweden, people celebrate the Summer Solstice by eating the first strawberries of the season.
In ancient Egypt, summer was the start of the new year. The rising of the star Sirius roughly coincided with the summer solstice and the annual flooding of the Nile River.
Summer Solstice Folklore
- Deep snow in winter, tall grain in summer. –Estonian proverb
- When the summer birds take their flight, goes the summer with them.
- If it rains on Midsummer’s Eve, the filbert crops will be spoiled. –Unknown
- One swallow never made a summer.
- Easterly winds from May 19 to the 21 indicate a dry summer.
- If there are many falling stars during a clear summer evening, expect thunder. If there are none, expect fine weather.