Map from Google - European_Russia

The European part of Russia is the one located west of the Ural Mountains.
Because of its large size, this country has different types of climate, but almost everywhere winter is freezing, and summer is moderately rainy.

The main climatic zones are the following: arctic and subarctic in the far north (with only a long cold winter and a cold summer), continental in the inland areas (with cold winters and summers which are progressively warmer as you head south), moderately continental in the western Baltic region (with freezing winters, though more temperate than in the inland regions, and mild summers, with frequent rains, possible thunderstorms in the afternoon and cool nights), Mediterranean on the coast bordering the Black Sea (with mild and rainy winters, and warm and sunny summers), arid continental in the Pontic-Caspian steppe region (with cold winters, hot summers and low rainfall).

Proceeding from west to east, there is typically a sharpening on the continentality (especially with regard to the winter cold) and a decrease in precipitation.

Russia is the cold country par excellence: apart from the climatic differences, the common feature of most of the country is the winter cold.
The European side is less cold than the Asian one, but here the lowest temperatures of the European continent are recorded.

This country is exposed to different influences, warm and cold, so that its climate is characterized by chronic instability, due to the absence of major mountain ranges (excluding the Caucasus in the south). The influence of Atlantic Ocean air masses is not remarkable, though they can bring a wet and mild weather; from the Arctic Ocean, the blizzard is able to bring dreadful snow storms in winter; from Siberia, frigid air masses in winter may arrive, and from Central Asia warm winds in summer, called Sukhoviei.

The only area with a mild climate, being sheltered from the winter frost, is the southern coast of the Black Sea, where the climate is almost Mediterranean, with mild and rainy winters and hot and sunny summers, but with possible thunderstorms.

Climate of the northern European Russia
The climate is Arctic in the northern islands of Russia (see Franz Josef Land), with an average temperature in the coldest months (which at high latitudes are February and March) around -10 °F, therefore colder than the Svalbard Islands (which belong to Norway), and an average in the warmest month (July) around 34 °F.
Here are the average temperatures of Franz Josef Land.
Average temperatures - Franz Joseph L.
Franz Joseph L.JanFebMarAprMayJunJulAugSepOctNovDec
Min (°F)-13-15-15-614283230237-6-13
Max (°F)0-4-4321323634281630

South of Franz Josef Land, in the islands of Novaya Zemlya, which separate the Barents Sea from the Kara Sea, the climate is Arctic in the northern tip, where the average in July is still around 34 °F, while it becomes progressively milder heading south: in Malyie Karmakuly, in the south-central area, it becomes subarctic, with about 4 months above freezing, from June to September, when the average temperatures remains nonetheless below 50 °F. In inland areas, especially in the northern island, there are hills which are home to perennial snows, already at a thousand feet above sea level.
Average temperatures - Malyie Karmakuly
Malyie KarmakulyJanFebMarAprMayJunJulAugSepOctNovDec
Malyie KarmakulyJFMAMJJASOND
Min (°F)1059213441413625147
Max (°F)121016192841504841322318

Along the northern coasts of mainland Russia, bordering the Barents Sea, the climate is subarctic, with a long and cold winter, followed by a cold summer, which lasts for three/four months. The Barents Sea remains ice-free even in winter, because of the last branch of the Gulf Stream. The average temperatures in winter are around 23 °F in the western part of the Kola Peninsula, and decrease progressively towards the east, until they reach about -4 °F in the eastern part (see Amderma). As we have said, along these coasts the summer is cold, with the temperatures that rise a few degrees above freezing in the warmest months, when highs are around 50/54 °F.

In the north of Russia, at a certain distance from the sea or along the shores of bays and sheltered inlets, there is a large area where the climate is cold continental, with a long, cold winter (often colder than in the previous area, due to the increased continentality), and a cool summer, in which the maximum temperatures get close to 68 °F. For example, in Murmansk, in a fjord on the Kola Peninsula, the average temperature in January is 12 °F, while in summer the temperature rises steadily above freezing for about 5 months and a half, from May to mid-October, and the average maximum in July is around 62.5 °F.
Average temperatures - Murmansk
Min (°F)5714233443484639301810
Max (°F)181827364557635950372821

Precipitation in Murmansk, not abundant, amounts to 19 inches per year, with a minimum in winter and spring, when light snowfalls occur, and a summer maximum. Here is the average precipitation.
Average precipitation - Murmansk
Prec. (in)

Along the shores of the White Sea, which freezes during winter, being sheltered from the Gulf Stream, the average January temperature in cities like Archangel and Onega, are around 9/10 °F, while in summer the maximum temperature reaches on average 68/72 °F.
Further east, in the vast plains of the Arkhangelsk Oblast and Komi Republic, there are areas where the lowest temperatures of the European continent have been recorded: -62 °F in Vorkuta (in 1978), and -69 °F in Pechora (in 1946).
Here are the average temperatures in Pechora, located at a latitude of 65 ° N.
Average temperatures - Pechora
Min (°F)-9-67183245524639277-4
Max (°F)7925375064726350361910

However, here in summer the average maximum temperature stays around 72 °F, with short periods above 85 °F. The rainfall is around 21.5/23.5 inches per year, and summer is the rainiest season (winter is too cold to have substantial precipitation, which, however, are frequent and weak, in the form of light snow, for many months,).

Climate zone of the Central European Russia
Further south, we enter into a wide flat area that includes Moscow, St. Petersburg and the major cities of European Russia. This area has a continental climate, with cold winters, but the temperatures remain below freezing for a shorter time than in the previous northern area. Summer is warm, and rainfall is frequent throughout the year, though with a summer maximum. In this vast area, the climate becomes progressively more continental as you move towards the east, mainly because of the colder winter, so much so that in Ufa, more than 600 miles east of Moscow, the average in January is 8.5 °F, therefore definitely lower than in the capital (see below), while the summer become slightly warmer.

In St. Petersburg, the influence of the sea is not substantial, because the Gulf of Finland during winter is often frozen. Winter is freezing: the average in January is 17.5 °F, although a little less cold than in Moscow. On the contrary, in the other seasons the maritime influence is evident, so that the summer is mild, with highs around 70/72 °F, but humid and rainy. August is usually more rainy than July. Occasionally, however, warm air masses from the continental area can arrive here (which is reminiscent of the descriptions of Dostoevsky's hot and muggy St. Petersburg).
Average temperatures - St Petersburg
St PetersburgJanFebMarAprMayJunJulAugSepOctNovDec
Min (°F)121221324352575546372818
Max (°F)232334466168726859463627

In St. Petersburg, precipitation is not abundant during the long winter months, when it occurs often in the form of light but frequent snowfalls, while they are more abundant in summer (August is the rainiest month). Here is the average precipitation.
Average precipitation - St Petersburg
St PetersburgJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec. (in)

The sea in Saint Petersburg is cold all year round, and as mentioned in winter it can freeze.
Sea temperature - St Petersburg
St PetersburgJanFebMarAprMayJunJulAugSepOctNovDec
Sea (°F)343232343946555955484337

St. Petersburg

In the great Russian plain, winters used to be colder: the average temperature in recent decades has increased by a few degrees, and cold waves from Siberia have become more rare. In Moscow the January average temperature of the last decades is 16 °F; the average daily temperature remains below freezing from November to March. Summer is warm, with a July average of 64.5 °F, but sometimes it can get hot. In summer there's no shortage of rainy days, while in periods of sunshine and good weather, some thunderstorms may break out in the afternoon.
Average temperatures - Moscow
Min (°F)101221364654575445362716
Max (°F)212536506472737259463425

Outside of the main territory, in the west, between Poland and Lithuania, we find the small exclave of Kaliningrad (formerly Königsberg). Here the climate is Baltic semi-continental, with cold winters (with frequent snowfall, though generally not abundant), and mild summers.
Average temperatures - Kaliningrad
Min (°F)212328364552555448413427
Max (°F)303241526370727263544336

Precipitation in Kaliningrad amounts to 31.5 inches per year, with a minimum in spring, and a maximum in summer and autumn. Here is the average precipitation.
Average precipitation - Kaliningrad
Prec. (in)

The Baltic Sea does not invite you to swim, however, the water temperature reaches 64 °F in August.
Sea temperature - Kaliningrad
Sea (°F)393737394655616461544843

Climate zone of the Southern European Russia
In the southern region of Russia, in the plains between Ukraine and Kazakhstan, winters are still cold but shorter, while summers begin to be hot. Rainfall is more scarce, so that the climate is steppe.
In Volgograd, where the average temperature in January is 21 °F, during the summer highs are normally around 85 °F, but sometimes they can reach 105 °F; only 13.8 inches of rain fall in a year.

The only part of the entire European Russia where the average in January clearly exceeds freezing, is the Black Sea coast. Should be noted, however, that in this area the winter is not mild everywhere: it's still cold in the Sea of Azov, where the average temperature in January is 31 °F, while along the coast of the Black Sea it gradually increases, from 35.5 °F in Anapa, to 44 °F in Sochi. So, the only really mild area is that of Sochi, and in fact this was the winter vacation resort for the Soviet nomenklatura: while in the northern coast of the Black Sea some outbreaks of cold air are possible, in Sochi the northern wind blow as a warm and dry down-slope wind coming from the mountains. In summer, the temperature is high: the average in July and August is 74/75 °F.
Average temperatures - Sochi
Min (°F)393741485563686861554643
Max (°F)505054637077818277685954

On the other hand, in this area it rains a lot all year round, even in summer, due to showers and thunderstorms occurring in the afternoon. In the northern coast of the Black Sea it rains less, so that in summer only 1.2/1.6 inches per month fall, compared with more than 4 inches per month in Sochi. Here is the average precipitation in Sochi.
Average precipitation - Sochi
Prec. (in)

The sea temperature in Sochi is warm enough for swimming in summer, especially in July and August, when it touches 75/77 °F.
Sea temperature - Sochi
Sea (°F)504848526170757773665952

In the Caspian Sea, the situation is quite different, and the climate is not so mild. Along the northern coast, the climate is semi-desert, with hot summers, when the average is around 75/77 °F in July and August, and cold winters, with an average in January of 23 °F in Astrakhan, and 28.5 °F in Kaspiyskiy. More to the south, along the coast of Dagestan, winter becomes progressively less cold and a little less arid: the average in January reaches 35.5 °F in the southern part of Dagestan, near the border with Azerbaijan.
Average temperatures - Astrakhan
Min (°F)161627435463666354413225
Max (°F)283045647784908675594534

In Astrahan, precipitation amounts to only 8.4 inches. Here is the average precipitation.
Average precipitation - Astrakhan
Prec. (in)

In winter, the Caspian Sea is colder than the Black Sea, while in summer it becomes equally warm.
Sea temperature - Makhachkala
Sea (°F)433939465768757773645446

Between the two seas (the Caspian Sea is actually a huge salt lake), we find the Caucasus Mountains, where Mount Elbrus stands out, with its 18,510 feet. The climate varies with altitude and slope exposure: it becomes cold and snowy at high altitudes, while at low altitudes, at the foot of the mountains, it's continental, with cold winters: in Grozny, the average in January is 26.5 °F. On the contrary, summers are warm or hot: the average in July is 75 °F in Grozny and 68 °F in Vladikavkaz, at 2,100 feet above sea level.
Average temperatures - Grozny
Min (°F)212330415259646355433627
Max (°F)343748647582888677634837

The western part of the Caucasus is more rainy (and more snowy in winter) than the eastern one. Precipitation in Grozny, not abundant, amounts to 17.3 inches per year, and is scarce in winter, and relatively more abundant in late spring and summer. Here is the average precipitation.
Average precipitation - Grozny
Prec. (in)0.80.811.

When to go

The best time to visit most of European Russia is generally the summer (late May to early September in Moscow and St. Petersburg, only July and August in the northern areas), which allows to avoid the discomfort of the cold and bad weather, while in the southern regions (Caspian steppe areas, the foothills of the Caucasus), where the summer is hot, you may prefer May and September.

In St. Petersburg, even in summer there can be cool and rainy days; in June, here as in other areas located at high latitude, you can enjoy the famous white nights, described by Dostoevsky.

In Moscow, where in winter the temperature can drop to -22 °F and below, the summer can sometimes be hot, with highs about 85 °F and even above; in the afternoon there may be some thunderstorms, while sometimes days can be cool even in mid-summer, with maximum temperatures below 50 °F.

The worst time to stay in Russia is probably the thaw: unpaved roads are often impassable because of the mud and melting snow. Depending on the area and the years, this phenomenon, called rasputitsa, comes in different periods. In the Arctic it occurs in summer, while in Moscow it usually occurs on late March or early April, and it lasts for a fortnight. The Russians prefer the icy winter to these cold and wet periods.

If you intend to visit Russia in its winter look, the second half of February has longer days, and temperatures often less cold, though still below freezing.

What to pack

In winter: cold weather clothing, synthetic thermal long underwear, fleece, parka, wind jacket, warm boots. For Sochi and the Black Sea: warm clothes, sweater, jacket, raincoat or umbrella.

In summer: in Moscow and St. Petersburg: spring/autumn clothes, T-shirts and shorts for hot days, jacket and sweater for the evening and cooler days; raincoat or umbrella.
In the Arctic coasts and islands: warm clothes, down jacket, hat, gloves.
In the south, Caspian Sea and Black Sea: light clothing, sweatshirt or light jacket for the evening.