Happy summer solstice, the longest day of the year. What are you doing with all your extra daylight?
For us here at latitude 53.5ºN, it means 17 hours and 3 minutes of sunlight today (5:04 a.m. to 10:07 p.m.). The sun rises in the northeast and sets in the northwest.
According to this chart by Time and Date, civil twilight runs from 4:11 a.m. to 11:00 p.m. In a practical sense, that means it’s light outside from just after 4 a.m. to 11 p.m. This is a wonderful time for sitting out on restaurant patios or finishing up some gardening.
The long day length is one of the best things about living here. With daylight beginning at 4 a.m. Daylight Saving Time (DST), you can understand why I am a huge fan of the one-hour time shift. Who needs light to begin at 3 a.m. (on Standard Time)? But isn’t it nice to have daylight until 11 p.m. rather than 10 p.m.?
Astronomical twilight goes on throughout the night, hence my often-used term “indigo sky.”
By contrast, during winter solstice the sun rises at 8:48 a.m. in the southeast and sets at 4:16 p.m. in the southwest.
Sunrise/sunset times and their angles
|Date||Sunrise||Sunset||Altitude at Meridian
|37° at 1:41 pm
|60° at 1:35 pm
|36° at 1:26 pm
|13° at 12:32 pm
*Standard Daylight Time (rest are Daylight Saving Time)
Data compiled from Time and Date website for Edmonton, Alberta, Canada.
Look at how low our sun is in December–only 13° above the horizon at solar noon! On June 21, it is only 60° above the horizon. That is the price we pay for being farther north (latitude 53.5°N).
By contrast, Longview, Texas (latitude 32.5°N) east of Dallas has a sun altitude of 34° above the horizon on December 21. On June 21, the city has 14 hours and 17 minutes of sunshine, with the sun 81° above the horizon at solar noon.
To understand the sun’s degrees and angle differences between summer and winter, view this image (from Introductory Astronomy: The Celestial Sphere) of sun paths for the northern hemisphere. In the summer, the sun path is longer and runs from NE to NW. At equinox, the sun path is E to W. In the winter, the sun path is shortest and runs from SE to SW (sunrise to sunset).
Here in central Alberta, we gain nearly 5 hours of light from December to March, and an additional almost 5 hours from March to June–totalling a whopping 10 hours of extra light in the summer versus winter.
By fall equinox, we will be rapidly losing daylight at a rate of 4 minutes and 12 seconds of per day!
First Day of Summer: Summer Solstice 2017 (The Old Farmer’s Almanac)
First Day of Seasons 2017 (The Old Farmer’s Almanac)
How much does day length vary from winter to summer where you live?
Meteorological versus astronomical summer
Meteorological summer runs from June 1st to August 31st. The seasons are split equally into three months each in a way that coincides with our Gregorian calendar:
Spring: March, April, May
Summer: June, July, August
Fall: September, October, November
Winter: December, January, February
Astronomical summer runs from June 21, summer solstice, to Sept. 22, fall equinox.
(Source: Met Office, UK.)
In Edmonton, however, the seasons look more like this:
Spring: April, May
Summer: June, July, August
Fall: September, October
Winter: November, December, January, February, March
Sometimes, winter begins in October and/or runs well into April. Sometimes, we have only six (summer 2008) to eight weeks of true summer. An example of a year without a summer was 1995, although September saw summer-like warmth in the daytime, with temperatures up to 26°C (79°F). It’s a pity the outdoor pools and spray parks had closed for the season by then. Seven full months of winter followed that emulated the winter described by Laura Ingalls Wilder in her book The Long Winter (Little House series).
Summers 1993 and 1994, however, were quite hot, and 1994 was long with spectacular thunderstorms in early July. Summer 1998 brought a long, hot growing season that began in April. We grew enough cucumbers to fill a 60-litre container one and a half times. We’d never been able to grow cucumbers successfully afterward.
When Does Summer Start? (Met Office)
Solstice and equinox
- June solstice (longest day in the northern hemisphere)
- December solstice (shortest day in the northern hemisphere)
What is Edmonton like on The Longest Night of the Year?
- Daylight data: timeanddate.com
- Introductory Astronomy: The Celestial Sphere
- Met Office (UK)
- NOAA (National Oceanic and Atmospheric Administration)
- The Old Farmer’s Almanac