The average daily temperature in July is 22 °C (72 °F); summer maximum is about 34 °C (93 °F), winter minimum is about −35 °C (−31 °F). The record low temperature is −35.9 °C (−33 °F), recorded in 1883. The average annual temperature is +5.4 °C (42 °F).

The River Neva within the city limits usually freezes up in November-December, break-up occurs in April. From December to March there are 123 days average with snow cover, which reaches the average of 24 cm (9 in) by February. The frost-free period in the city lasts on average for about 135 days. The city has a climate slightly warmer than its suburbs. Weather conditions are quite variable all year round.

Average annual precipitation varies across the city, averaging 600 mm (24 in) per year and reaching maximum in late summer. Soil moisture is almost always high because of lower evapotranspiration due to the cool climate. Air humidity is 78% on average, while overcast is 165 days a year on average.

Some weather data sourced from BBC
Some text and data sourced and adapted from WikiPedia