June 21 is the astronomical beginning of summer in the northern hemisphere and thus the longest day and shortest night of the year. It’s only really dark for about two hours.
Am Tuesday, June 21, 2022 at 11:13 am the sun reaches its northernmost point. It is then perpendicular to the northern tropic. In the northern hemisphere we experience the longest day, in Switzerland it lasts almost 16 hours from sunrise to sunset. At the end of June, however, the day length varies only minimally from day to day, only in the course of July does it decrease by more than a minute per day. In a month, on July 20th, the day will already be half an hour shorter than it is now.
Just dark for a moment
You may have had sleepless nights over the weekend because of the heat and noticed that the birds started whistling again very early. Around the longest day on June 21st, we also experience the shortest nights. There are currently around 8 hours between sunset and sunrise. Due to the long twilight phases, however, it only gets really dark between 12:30 a.m. and 2:30 a.m. Shortly after 4 a.m., the first birds begin their concert, and as a rule, redstarts and black redstarts are the earliest (according to NABU). The blackbird then begins to sing about three quarters of an hour before sunrise.
The latest sunset is yet to come
While the earliest sunrise took place last Thursday, the latest sunset on June 26 is yet to come. Because of the equation of time, these are not synchronous (see “More on the topic”).