St. Petersburg experienced the first frost on Sunday, October 6. Amid clear skies and light winds, the mercury dropped to −2, which is more typical for late October. But in this case, the Arctic invasion was stronger than the warming influence of the Baltic.
The nighttime cooling of the Arctic air was so intense that a temperature record was almost broken. The day was one degree short of equalling the absolute record for that day set in 1986.
Wet snow was also a contributing factor. A temporary snow cover formed in some parts of St. Petersburg on Monday morning.
A southern cyclone that covered Central Russia with snow
did not affect St. Petersburg, but pulling colder air into its circulation, it ensured unstable and cold weather at the beginning of the week .
Western processes will start intensifying in the atmosphere on Wednesday. The breath of the Baltic and then of the Atlantic will make the weather moderately warm and wet. Light rains are expected in the second half of the week, and temperatures will be back to normal. The threat of night frost will be over, and the mercury will rise to +10 in the afternoon.