White nights began in St. Petersburg

In St. Petersburg, located at northern latitude, the period of white nights began, which will end on July 2. At this time, daylight hours will be about 19 hours. The duration of the longest day - June 21-22 - will be 21 hours 35 minutes, reports Interfax.

According to the definition of experts, this time is called civil twilight, which is understood as the period of time from entering the horizon of the upper edge of the solar disk until the immersion of the sun under the horizon does not exceed 6-7 degrees.

In general, the immersion of the sun even at midnight can be so small that evening civil twilight pass into the morning without the usual period of night darkness. At this time, in open areas you can do any work, write and read.

In addition to the geographical latitude and declination of the sun, the real duration of twilight in this paragraph of the globe on this day of the year depends on the terrain, cloud cover, snow cover, lunar lighting and other factors.

In addition to St. Petersburg, white nights are characteristic of Petrozavodsk. There this period is longer - from May 27 to July 17, and in the Arkhangelsk and Murmansk regions a polar day has already come, which lasts 60 days.