Map from Google - Armenia

In Armenia the climate is continental, with cold winters and hot summers, and usually with little rain. Armenia is a mountainous country, and only a small portion of its territory is located below 1,000 metres above sea level, while there are no plains: the climate becomes both colder and wetter (and snowy in winter as well) with increasing altitude, while at lower elevations the rains are scarce and the summer is very hot. The driest region, where precipitation drops below 300 millimetres per year, is the west, which includes the capital, and its altitude goes below 1,000 metres.
In winter, cold air masses predominate, and after having reached the country from the north, they tend to stagnate in the valleys, causing severe frosts; spring is a volatile season and sees the most frequent rains, though generally they remain not abundant, because as mentioned, this country is generally arid, at least at lower elevations. Summer is dry and sunny, but with some afternoon thunderstorms in the mountains.
From the mountains, a down-slope dry and warm wind similar to Föhn or Chinook can reach the valleys, especially in winter, but also in spring and autumn.

The capital Yerevan is located at 800 metres above sea level, therefore at the lowest altitudes of the country, and has an average temperature in January of -3.5 °C, and of 25 °C in July, with a maximum average temperature of 33 °C, but also with peaks of about 40 °C. So here summer is hot despite the altitude, even though the humidity is low and the breezes from the mountains bring a bit of relief. Winter is rather cold: in a year there are on average a hundred days with minimum temperatures below freezing, and snow, though usually not abundant, can cover the ground for weeks. In winter the mountains are covered with snow, and the inhabitants of the capital go skiing in Tsaghkadzor.
Here are the average temperatures of Yerevan.
Average temperatures - Erevan
Min (°C)-8-606101417171271-4
Max (°C)141119242933322821124

In Yerevan, precipitation amounts to only 275 mm per year, therefore it's at semi-desert levels, however the rainiest season is spring, with 30/40 mm per month, while summer is the least rainy season, and it's also sunny, here as elsewhere in the country.
Here is the average precipitation.
Average precipitation - Erevan
Prec. (mm)202530354520101010252525275

From Yerevan, you can see on the horizon the spectacular Mount Ararat, which however is located in the Turkish territory.


In the north, Gyumri (formerly Leninakan) is very cold due to the altitude, being located at 1,500 metres, and has an average temperature in January of -8.5 °C, but in the worst times it can drop to about -35 °C. Summer is quite warm, at least if you consider the altitude: highs in July and August are about 26 °C, and sometimes it can get even hot, although nights remain cool.
Average temperatures - Gyumri
Min (°C)-14-12-6058121271-3-9
Max (°C)-3-141318222626231670

In Gyumri, 525 mm of rain (or snow) per year fall, confirming the rule that the areas located at higher altitudes receive more rainfall. Here, even in summer sometimes it can rain because of afternoon thunderstorms, which can occur in the mountains, and therefore the driest season (at least in quantity) is winter, when precipitation, though not abundant, always occurs in the form of snow, while the wettest period runs from April to June: in May and June the thunderstorms are a bit more frequent, because a bit of cold air can still arrive at high altitudes, increasing the thermal contrasts, while in July and August the atmosphere becomes warmer even at high elevations, and therefore it becomes more stable.
Here is the average precipitation.
Average precipitation - Gyumri
Prec. (mm)252535608070603535402535525

Sevan, located at 2,000 metres above sea level, on the lake of the same name, in winter is not colder than Gyumri, because the waters of the lake slightly mitigate the climate: in fact the average in January is -8 °C, while the average in August is just 15 °C.
Average temperatures - Sevan
Min (°C)-13-13-12-61591050-7-11
Max (°C)-3-21712161920171260

In a year, the rainfall amounts to about 500 mm, again with a maximum between spring and early summer, and a minimum in winter. Here is the average precipitation.
Average precipitation - Sevan
Prec. (mm)152535608580453525503020495

When to go

To visit Yerevan and the areas below 1,000 metres, which in summer can be very hot, the best times are spring and autumn, especially the month of May, and from mid-September to mid-October. At higher altitudes, such as in Gyumri and Lake Sevan, you can choose instead summer, from June to September. Wanting to find a compromise for the whole country, you can choose June and September, or even July and August for those who can stand the heat.

What to pack

In winter: very warm clothes, fleece, down jacket, hat, scarf, gloves.
In summer: in Yerevan, light clothes for the day, sun hat, sweatshirt and light jacket for the evening; in Sevan and above 2,000 metres, spring/autumn clothes, sun hat, sweater and warm jacket for the evening, possibly a raincoat or umbrella.