Norway is a Nordic country, but it is affected by the Gulf Stream, so its climate is less cold than you might think, especially along the west coast. However, the country is very extended in latitude, and it has a rugged coastline, plateaus and mountain ranges, so there are different climates to be taken into account.
The ocean, whose surface temperature remains a few degrees above freezing even in winter, tempers the winter weather, while it remains cool in summer, therefore it reduces the annual temperature range along the coast. On the contrary, in the interior this mild influence is felt little, because in Norway there are almost no plains, hence, highlands and mountain ranges are able to hinder the penetration of mild currents coming from the sea.
The following map shows the climate zones in Norway.



The west coast has a cool, wet climate, characterized by the frequent passage of weather fronts, so that clouds, rain and wind dominate throughout the year.
During winter, the temperature remains slightly above freezing (0 °C or 32 °F) in the southern part, so that Bergen, the second largest city in the country, has an average temperature in January and February around 2 °C (35.5 °F). Precipitation does not always occur in the form of snow, but it often occurs in the form of a continuous and cold drizzle.
Here are the average temperatures in Bergen.
Average temperatures - Bergen

Bergen	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Bergen	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	0	-1	1	3	7	10	12	12	9	7	3	1
Max (°C)	4	4	6	9	14	17	18	17	14	11	7	5
Min (°F)	32	30	34	37	45	50	54	54	48	45	37	34
Max (°F)	39	39	43	48	57	63	64	63	57	52	45	41

In Bergen and on the west coast, the sun, which is almost never seen from November to January, despite the length of the days rarely shines even in summer, as cloudy skies prevail.
Sunshine - Bergen

Bergen	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Bergen	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	1	2	3	5	6	6	5	5	3	2	1	0

The temperature of the sea at Bergen is cold, but it's mild for the latitude, as we can see from the following table.
Sea temperature - Bergen

Bergen	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Bergen	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	7	6	6	6	8	11	14	15	13	11	9	8
Sea (°F)	45	43	43	43	46	52	57	59	55	52	48	46

Moving to the north, the temperature gradually decreases, but the average daily temperature reaches the freezing point only around the 65th parallel, just below the Arctic Circle. It's remarkable that the Lofoten and Vesteralen Islands, located above the Arctic Circle itself, even in winter can sometimes experience rain instead of snow. Continuing to the north, the temperature goes down to a few degrees below freezing, and snow becomes frequent even along the coast, but at this point we enter in the climate area of the northern coast (as shown in the map above).
The sea, which in winter makes the air milder, during summer cools down the air, so that in July and August, maximum temperatures along the west coast are around 15 °C (59 °F), and minimum temperatures around 10 °C (50 °F). However, if you move a few kilometres (or miles) inland, you can experience an increase in daytime temperatures, which can rise by a few degrees, and this happens in Bergen and other towns located not directly on the ocean coast, but inside a fjord.
Precipitation is quite common along the western slope. In the southern area, it is also abundant: in Bergen the average annual precipitation is about 2,200 millimetres (87 inches), but in cities located at the foot of the hills it can exceed 3,000 mm (118 in).
Here is the average precipitation in Bergen.
Average precipitation - Bergen

Bergen	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Bergen	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	190	150	170	115	105	130	150	190	285	270	260	235	2250
Prec.(in)	7.5	5.9	6.7	4.5	4.1	5.1	5.9	7.5	11.2	10.6	10.2	9.3	88.6
Days	21	17	19	17	17	16	18	19	23	24	22	22	235

Continuing to the north along the coast, precipitation is still frequent, but it becomes less abundant, and drops below 1,000 mm (40 in) in the coast to the north of Trondheim, although it can still reach 2,000 mm (79 in) in the slopes near the coast, where there are hills directly exposed to the westerly winds.

The north coast is a bit colder than the western one, and has a subpolar oceanic climate, although a branch of the Gulf Stream arrives here as well. The result is that the open sea does not freeze even at these latitude, and this does not happen anywhere else in the world. The following table shows the temperature of the sea at the North Cape.
Sea temperature - North Cape

North Cape	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
North Cape	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	5	4	4	4	5	7	9	10	9	7	6	6
Sea (°F)	41	39	39	39	41	45	48	50	48	45	43	43

The average winter temperatures, however, are below freezing, and tend to decrease as we move towards the east: the average in January and February ranges from -2 °C to -6 °C (28 °F to 21 °F), from the west to the east. At North Cape, in winter the temperatures are similar to those of Oslo, even though here the winter is longer. The northern coast is close enough to the Pole, therefore is subject to polar winds, which can be furious, especially in winter and spring.
Average temperatures - North Cape

North Cape	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
North Cape	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-6	-6	-4	-2	2	5	8	8	5	2	-2	-4
Max (°C)	-2	-2	-1	1	5	9	13	12	9	5	1	-1
Min (°F)	21	21	25	28	36	41	46	46	41	36	28	25
Max (°F)	28	28	30	34	41	48	55	54	48	41	34	30

In summer, July and August, which have an average temperature around 10 °C (50 °F), are the mildest and also the quietest months, with the lowest risk of wind. Near the Arctic Circle, you can see the midnight sun around the summer solstice (21 June), and for a period much longer as you head north. At the North Cape, the sun never sets from mid-May to late July.
At North Cape, precipitation amounts to about 800 mm (31.5 in) per year. Summer is the least rainy season, although there are still 9/10 days with rain per month. Here is the average precipitation.
Average precipitation - North Cape

North Cape	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
North Cape	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	95	75	65	60	40	40	45	50	60	85	80	100	795
Prec.(in)	3.7	3	2.6	2.4	1.6	1.6	1.8	2	2.4	3.3	3.1	3.9	31.3
Days	18	15	15	14	11	10	9	10	14	18	17	19	170

Even here on the north coast, within the fjords there's a decrease in the winter temperatures (so that in the deepest fjords the sea can freeze during winter), and an increase in the summer temperatures: in fact here this phenomenon is even more pronounced than on the west coast. For example, in Lakselv, located in the southern part of a fjord, more than 120 kilometres (75 miles) away from the ocean coast, the average in January is -10 °C (14 °F), while to the north, on the ocean coast, it is just -4 °C (25 °F).

The south-east coast of Norway, on the Skagerrak strait that separates the country from Denmark, is less influenced by the ocean than the west coast, therefore it is less humid and less rainy than the area of Bergen, a bit colder in winter (with average temperatures just below freezing), and warmer in summer, with highs around 20 °C (68 °F), so the stay in the latter season is usually pleasant, and you can even hope to see some sunshine.
Average temperatures - Kristiansand

Kristiansand	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Kristiansand	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-5	-5	-2	1	6	9	11	10	8	5	0	-3
Max (°C)	1	2	4	9	14	19	20	19	16	11	6	3
Min (°F)	23	23	28	34	43	48	52	50	46	41	32	27
Max (°F)	34	36	39	48	57	66	68	66	61	52	43	37

In Kristiansand, precipitation amounts to 1,300 mm (51 in) per year, so it is quite abundant, but it's still much lower than in Bergen.
Average precipitation - Kristiansand

Kristiansand	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Kristiansand	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	120	80	85	60	85	75	90	120	140	165	165	115	1300
Prec.(in)	4.7	3.1	3.3	2.4	3.3	3	3.5	4.7	5.5	6.5	6.5	4.5	51.2
Days	19	15	16	12	14	12	13	17	18	19	20	19	194

The fjords of Norway, which we have already mentioned, have different microclimates depending on shape and size, and also on slope exposure, but generally, as you penetrate inland, they become less rainy throughout the year, and more continental, that is, colder in winter and warmer and sunnier in summer. For example, the city of Trondheim, located inside a large and deep fjord that opens into the western coast, has an average temperature of -2 °C (28.5 °F) in January, and of 15 °C (59 °F) in July, and therefore it can be included in the continental climate zone, while in Kristiansund, on the west coast and at the same latitude, the average goes from 1 °C (34 °F) in January, to 13 °C (55.5 °F) in July.
Average temperatures - Trondheim

Trondheim	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Trondheim	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-5	-5	-2	1	5	8	11	10	7	3	-1	-4
Max (°C)	1	2	4	8	13	16	19	18	14	9	4	2
Min (°F)	23	23	28	34	41	46	52	50	45	37	30	25
Max (°F)	34	36	39	46	55	61	66	64	57	48	39	36

In Trondheim, about 875 mm (34.5 in) of rain or snow per year fall; the wettest seasons are summer and autumn. Here is average precipitation.
Average precipitation - Trondheim

Trondheim	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Trondheim	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	80	65	55	45	50	70	90	90	90	80	75	80	875
Prec.(in)	3.1	2.6	2.2	1.8	2	2.8	3.5	3.5	3.5	3.1	3	3.1	34.4
Days	14	13	12	10	11	12	12	14	14	14	13	14	153

The interior of Norway has a continental climate, with cold and snowy winters, and mild summers. Typically the interior is covered with hills and mountains, and the temperature decreases with altitude, so that at high elevation we find a mountain climate. The snowline in Norway is quite low, about 1,500 metres (5,000 feet).
The coldest area of the country is the Norwegian part of Lapland, which corresponds to the southern part of the Finnmark County. Here the winter is really frigid, in fact the temperature can drop to -50 °C (-58 °F) in the worst moments. Summer is short but intense: in the three months, during which the temperature rises above freezing even at night, the vegetation explodes, and the days are very long. Sometimes it can even get hot, so that the daytime temperature can reach 30 °C (86 °F), while nigths remain cool or even cold.
Average temperatures - Karasjok

Karasjok	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Karasjok	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-23	-22	-17	-9	-1	5	8	6	2	-5	-14	-21
Max (°C)	-12	-10	-4	1	7	15	18	15	9	2	-5	-10
Min (°F)	-9	-8	1	16	30	41	46	43	36	23	7	-6
Max (°F)	10	14	25	34	45	59	64	59	48	36	23	14

In this area, precipitation is much scarcer than in the rest of Norway, both for the distance from the sea and for the cold, so that it does not reach 400 mm (16 in) per year, although in summer, when temperatures rise, precipitation, which in this season occurs in the form of rain, becomes more abundant. Here is average precipitation in Karasjok.
Average precipitation - Karasjok

Karasjok	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Karasjok	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	20	15	15	15	25	40	70	60	40	35	20	15	365
Prec.(in)	0.8	0.6	0.6	0.6	1	1.6	2.8	2.4	1.6	1.4	0.8	0.6	14.4
Days	6	5	5	5	6	8	11	11	9	8	7	6	87

In Karasjok, the sun, which in winter is hardly ever seen (also because from December to mid-January it does not even rise), in summer it rarely appears, despite the length of the days (from May 20 to July 25 it never sets).
Sunshine - Karasjok

Karasjok	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Karasjok	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	0	1	4	6	5	6	6	4	2	2	0	0

Even in the centre-east of Norway, on the border with Sweden, ie the northern part of Hedmark and the eastern part of Sør-Trøndelag, very marked continental features are found, because of the distance from the sea, but also of the position on the eastern side, and of altitude, as this area is occupied by a plateau, between 500 and 1,000 metres (1,600 and 3,300 feet) above sea level. Here, during winter the temperature can drop below -40 °C (-40 °F).



The area of Oslo, along the south-eastern part of Norway, has a Baltic (slightly continental) climate: winters are cold, with temperatures a few degrees below freezing in the winter months, and frequent snowfall. During winter, mild air masses from the Atlantic ocean can sometimes penetrate even here, so that rain may fall instead of snow, while on other occasions, cold spells are possible, due to air masses coming from Russia, which may lower the temperature to around -25 °C (-13 °F). The average temperature hovers around freezing in late November and early March, and is mild in the three summer months (June, July and August), with highs around 20/22 °C (68/72 °F). Rainfall is moderate, but well distributed throughout the year, with a maximum between summer and autumn, and a minimum in spring. Like other cities of the country, Oslo is located in a fjord, more than 80 kilometres (50 miles) deep.
Average temperatures - Oslo

Oslo	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Oslo	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-5	-5	-2	2	7	11	13	12	8	4	-1	-5
Max (°C)	0	0	4	10	16	20	22	21	16	9	4	0
Min (°F)	23	23	28	36	45	52	55	54	46	39	30	23
Max (°F)	32	32	39	50	61	68	72	70	61	48	39	32

The sun in Oslo is rarely seen from November to January, while from May to August it shines for a little less than half the time (compared to the length of the days).
Sunshine - Oslo

Oslo	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Oslo	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	1	3	4	6	7	8	8	7	5	3	2	1

The sea temperature in the Oslo fjord reaches 17 °C (63 °F) in July and August.
Sea temperature - Oslo

Oslo	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Oslo	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	5	4	4	6	10	14	17	17	15	12	9	6
Sea (°F)	41	39	39	43	50	57	63	63	59	54	48	43

Finally, there are the northern islands.

The island of Jan Mayen, situated between the Atlantic Ocean and the Arctic Ocean, has a subarctic climate.

Further to the north, we find the Svalbard archipelago, which is the northernmost part of Norway, and is colder in winter.


The best time to go to Norway is the summer, from June to August. Temperatures are very cool along the coast and in mountainous areas, and even cold along the northern coast. Sometimes it can even be a bit hot during the day, while nights remain cool. In Lapland, temperatures are a bit more variable, so it can get hot during the day, but also cold at night.
In Norway there's no shortage of rain even in summer, especially along the western coast. June is a bit cooler than July and August, but it is (relatively) drier and sunnier, and has longer days, with the white nights in the south and the midnight sun in the north.
For skiing, the month of March is preferable than the winter months, because the temperature is less cold and the days are longer.
In the northern islands, temperatures are definitely low even in summer, but at least they are above freezing, albeit slightly.
As we said, the ocean, which has a surface temperature of 5/6 °C (41/43 °F) in winter, remains cool during the summer, and reaches 15 °C (59 °F) in August at Bergen, and only 11 °C (52 °F) at Tromsø: with these temperatures, sea bathing takes a lot of courage! It goes a bit better in the Skagerrak strait and near Oslo, where the water temperature reaches 17 °C (63 °F) in July and August.


In winter: for Oslo, as well as inland and northern areas: very warm clothes, synthetic thermal long underwear, fleece, down jacket, hat, gloves, scarf. For the west coast: sweater, down jacket, hat, raincoat or umbrella.
In summer: spring/autumn clothes, being ready to add or remove the outer layer, t-shirt, but also long pants, sweatshirt or sweater; jacket, raincoat or umbrella.
It can be a useful to bring windbreaker and raincoat for the wind and the rain, especially along the coast and for a ferry trip in the fjords. In inland areas, in Oslo and along the southern coast, temperatures are generally mild, but a sweater for the evening is still advisable.
For the northern islands (Jan Mayen, Svalbard): warm clothing, down jacket, hat, gloves, windbreaker, raincoat.