https://www.thoughtco.com/longest-day-of-the-year-1435339The Longest Day of the Year
Learn Sunrise, Sunset, and Daylight Information for United States Cities
by Matt Rosenberg
Updated March 03, 2017
In the Northern Hemisphere, the longest day of the year will always be on or around June 21. On this date, the rays of the sun will be perpendicular to the Tropic of Cancer at 23°30' North latitude. This day is the summer solstice for all locations north of the equator.
On this day, the earth's "circle of illumination" will be from the Arctic Circle on the far side of the earth (in relation to the sun) to the Antarctic Circle on the near side of the earth.
The equator receives twelve hours of daylight, there's 24 hours of daylight at the North Pole and areas north of 66°30' N, and there's 24 hours of darkness at the South Pole and areas south of 66°30' S.
June 20-21 is start of summer in the Northern Hemisphere but simultaneously the start of winter in the Southern Hemisphere. It's also the longest day of sunlight for places in the Northern Hemisphere and the shortest day for cities south of the equator.
However, June 20-21 is not the day when the sun rises earliest in the morning nor when it sets latest at night. As we'll see, the date of earliest sunrise or sunset varies from location to location.
We'll start our tour of the solstice in the north, with Anchorage, Alaska and head south in the U.S. and then move on to international cities. It's interesting to compare the difference in sunrise and sunset in various locales around the globe.
In the information below, the date ranges for the "longest day" have been rounded to the nearest minute.
If we were to round to the second, the solistice on the the 20th or 21st would always be the longest day.
Anchorage, Alaska
Earliest Sunrise: 4:20 a.m. from June 17th through June 19th.
Latest Sunset: 11:42 p.m. from June 18th to June 25th
Longest Days: June 18th to June 22nd
Hours of Daylight on Longest Day: 19 hours and 21 minutes
Seattle, Washington
Earliest Sunrise: 5:11 a.m. from June 11th through June 20th.
Latest Sunset: 9:11 p.m. from June 19th to June 30th
Longest Days: June 16th to June 24th
Hours of Daylight on Longest Day: 15 hours and 59 minutes
Portland, Oregon
Earliest Sunrise: 5:21 a.m. from June 12th through June 17th.
Latest Sunset: 9:04 p.m. from June 23rd to June 27th
Longest Days: June 16th to June June 24th
Hours of Daylight on Longest Day: 15 hours and 41 minutes
New York City, New York
Earliest Sunrise: 5:24 a.m. from June 11th through June 17th.
Latest Sunset: 8:31 p.m. from June 20th to July 3rd
Longest Days: June 18th to June June 22nd
Hours of Daylight on Longest Day: 15 hours and 6 minutes
Sacramento, California
Earliest Sunrise: 5:41 a.m. from June 8th through June 18th.
Latest Sunset: 8:34 p.m. from June 20th to July 4th
Longest Days: June 17th to June June 23rd
Hours of Daylight on Longest Day: 14 hours and 52 minutes
Los Angeles, California
Earliest Sunrise: 5:41 a.m. from June 6th through June 17th.
Latest Sunset: 8:08 p.m. from June 20th to July 6th
Longest Days: June 19th to June 21st
Hours of Daylight on Longest Day: 14 hours and 26 minutes
Miami, Florida
Earliest Sunrise: 6:29 a.m. from May 31st through June 17th.
Latest Sunset: 8:16 p.m. from June 23rd to July 6th
Longest Days: June 15th to June 25th
Hours of Daylight on Longest Day: 13 hours and 45 minutes
Honolulu, Hawaii
Earliest Sunrise: 5:49 a.m. from May 28th through June 16th.
Latest Sunset: 7:18 p.m. from June 30th to July 7th
Longest Days: June 15th to June 25th
Hours of Daylight on Longest Day: 13 hours and 26 minutes
Because it is closer to the equator than any of the other U.S. cities profiled here, Honolulu has the shortest length of daylight on the summer solistice. The city also has far less variation in daylight throughout the year, so even winter days have close to 11 hours of sunlight.
International Cities continue on Page Two
Reykjavik, Iceland
Earliest Sunrise: 2:55 a.m. from June 18th through June 21st.
Latest Sunset: 12:04 a.m. from June 21st to June 24th
Longest Days: June 18th to June 22nd
Hours of Daylight on Longest Day: 21 hours and 8 minutes
If Reykjavik were just a few degrees further to the north, it would fall within the Arctic Circle and experience 24 hours of daylight on the summer solstice.
London, United Kingdom
Earliest Sunrise: 4:43 a.m. from June 11th through June 22nd.
Latest Sunset: 9:22 p.m. from June 21st to June 27th
Longest Days: June 17th to June 24th
Hours of Daylight on Longest Day: 16 hours and 38 minutes
Tokyo, Japan
Earliest Sunrise: 4:25 a.m. from June 6th through June 20th.
Latest Sunset: 7:01 p.m. from June 22nd to July 5th
Longest Days: June 19th to June 23nd
Hours of Daylight on Longest Day: 14 hours and 35 minutes
Mexico City, Mexico
Earliest Sunrise: 6:57 a.m. from June 3rd through June 7th.
Latest Sunset: 8:19 p.m. from June 27th to June 12th
Longest Days: June 13th to June 28th
Hours of Daylight on Longest Day: 13 hours and 18 minutes
Nairobi, Kenya
Earliest Sunrise: 6:11 a.m. from November 3rd through November 7th.
Latest Sunset: 6:52 p.m. from February 4th to June 14th
Longest Days: December 2nd to January 10th
Hours of Daylight on Longest Day: 12 hours and 12 minutes
Nairobi, which is merely 1°17' south of the equator, has exactly 12 hours of sunlight on June 21 when the sun rises at 6:33 a.m. and sets at 6:33 p.m. Because the city is in the Southern Hemisphere, it experiences its longest day on December 21.
Nairobi's shortest days, in mid June, are just 10 minutes shorter than the longest days in December. The lack of diversity in Nairobi's sunrise and sunset throughout the year provides a clear example of why lower latitudes don't need Daylight Saving Time - sunrise and sunset are almost at the same time year-round.
This article was edited by Allen Grove in September, 2016
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