Like much of European Russia, the climate of Moscow is humid continental. This means warm summers, which can sometimes turn muggy, and long, cold winters. In the winter, Moscow temperatures can reach 10 degrees F and sometimes much lower.
Typical Moscow summer daytime temperatures are in the low 70s. However, heat waves can occur anytime between May and September, during which daytime temperatures can reach the low 90s. This kind of extreme heat is more common now than it used to be. Record summer temperatures were set in 5 of the last 10 years. During the extreme heat wave of 2010, Moscow reached an alltime high temperature of 102.2 degrees. By contrast, during the first half of the 20th century, light night frost in late summer was common.
Moscow winters are bitterly cold. When averaged over 30 years, average winter nighttime temperatures in Moscow are around 14 degrees. Occasional warm spells take the temperature over the freezing point.
Although they are cold, Moscow winters are still roughly 20 degrees warmer than those in inland Siberia. The difference is because Moscow is closer to large bodies of water. However, the difference between a record -44 degrees in Moscow and the -60s of Siberia really doesn't matter all that much for practical purposes when there are only 6 hours of daylight in the depths of winter.
However, over the last 10 years, the winters in Moscow have become warmer than they used to be. Now, only January and February have average nighttime temperatures of below 20 degrees (17.2 and 13.8 degrees respectively). Daily maximum temperatures in Moscow only stay below freezing between December and early March. Previously, daily averages at the freezing point used to set in around November and not let up until April.
Spring and fall in Moscow are the best times to visit Moscow, especially late spring in May and early June. At these times, the temperature is generally mild and most of the snowcover is gone. However, keep in mind that the weather can change abruptly during these seasons.
Unfortunately, the beautiful Moscow springs may be growing shorter. Winter snowcover commonly lingers as late as May. At the same time, May now marks the beginning of the summer heatwaves. The 2010 Eurasian heatwave endured in Moscow for most of June, July, and the first week of August.
On a year-round basis, the 30-year average temperature in Moscow is 41 degrees. In the last few years, that average has risen to 45 degrees.
Precipitation and storms
Winters are very dry in Moscow. Only about 10 inches of snow falls each year. However, that snow stays on the ground for the entire winter. Some amount of snowfall can be expected as late as May and as early as September.
Most of Moscow's precipitation falls as rain, both as steady rain and as thunderstorms. Half of all days in summer will see some rain. Occasionally Moscow will see severe storms, or even a rare windstorm or tornado. Severe windstorms happen about once a decade, while tornadoes are roughly twice as frequent. Most tornadoes are minor, but on June 3, 2009, an F3 tornado struck just outside Moscow.
The 2010 heatwave also caused widespread drought conditions in the Moscow area. This led to an unprecedent rash of wildfires which consumed forest and crops alike. Air quality throughout Moscow often suffered as a result.