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Average weather, temperature, rainfall, sunshine hours
In Dortmund, a German city located in the state of North Rhine-Westphalia, the climate is
sub-oceanic. Winters are cold but not freezing, while summers are mild or pleasantly warm.
The
Atlantic Ocean influences the climate, bringing clouds and rain for much of the year, and cold, unstable air from the North Sea. However, there can also be mild periods in winter, and warm to hot periods from late April to early October, because of air masses coming from the subtropical latitudes of the ocean.
The
wind blows frequently and can be intense, especially from November to March.
Dortmund is the largest city in the Ruhr area, a conurbation that includes several cities, among which Bochum, Bottrop, Dortmund, Duisburg, Essen, Gelsenkirchen, Hagen, Hamm, Herne, Mülheim an der Ruhr, and Oberhausen.
Precipitation is relatively abundant, about 800 millimeters (31.5 inches) per year, but above all, it is frequent and well distributed over the seasons. However, the rainiest season (at least in quantity) is summer, and the least rainy season is spring. Rainfall often occurs in the form of short shower or drizzle, whereas during the summer, thunderstorms can break out in the afternoon.
Winter, from December to February, is cold: daytime temperatures are on average a few degrees above freezing (0 °C or 32 °F), while at night, they are around freezing. Wind and humidity often exacerbate the feeling of cold.
However, different weather situations can occur.
When the westerlies blow, the temperature can be quite mild and can reach 10/12 °C (50/54 °F), but there may be wind and rain.
On the contrary, when the city is reached by
cold air masses from Russia, the temperature drops below freezing, for longer or shorter periods, even during the day. The temperature rarely drops below -15 °C (5 °F), however, it can do it during very cold periods, which used to be more frequent in the past. The coldest record is -27.8 °C (-18 °F) and was set in January 1942.
Snowfalls in Dortmund are quite frequent, though usually not abundant, and occur in the form of light snow, sometimes, however, snow can accumulate on the ground, and last for many days, if it occurs during cold waves.
Spring, from March to May, is an unstable season.
On the one hand, northwesterly currents can bring cold periods, so much so that in March, and sometimes until mid-April, it can still snow. In addition, some cold days, with highs around 10 °C (50 °F), can still occur in May, especially in the first half of the month.
On the other hand, southwesterly currents can bring very mild or quite warm periods, with highs above 20 °C (68 °F) in April and above 25 °C (77 °F) in May.
Summer, from June to August, is mild or pleasantly warm. The flow of Atlantic fronts does not cease even in this season. The wind blows quite often from the North Sea, which is not far, and rainfall is quite frequent as well.
However, there are pleasant periods, with daytime temperatures between 20 °C and 25 °C (68 and 77 °F), but also cooler periods, with daytime temperatures remaining below 20 °C (68 °F). At night, it can be a bit cold, since the temperature can drop below 10 °C (50 °F) even in July and August.
Sometimes, there can be
hot days, during which the temperature can reach 30/32 °C (86/90 °F), while more rarely, it can even exceed 35 °C (95 °F). The highest record is 39 °C (102.2 °F) and was set in July 2019. In August 2020, the maximum temperature fluctuated between 30 and 35 °C (86 and 95 °F) for nine consecutive days.
Autumn, from September to November, is initially pleasant in September, and sometimes also in early October (although there is no shortage of rainfall), then it gradually becomes more cold, dull, wet and windy. The first night frosts usually occur in November, but sometimes also in October.
Dortmund does not get a lot of
sun, especially from November to February, when the sun rarely shines. It goes a bit better from May to August, when the weather is variable, and between one disturbance and another, the sun can come out.
Best Time
The
best time to visit Dortmund runs from mid-May to mid-September, since it's the mildest of the year. July and August are the warmest months. However, it's better to bring a sweatshirt or sweater, a light jacket, and an umbrella, for cool and rainy days.
Dortmund - Climate data
In Dortmund, the
average temperature of the coldest month (January) is of
3 °C, that of the warmest month (July) is of
18.9 °C. Here are the average temperatures.
Dortmund - Average temperatures (1991-2020) |
| Month | Min | Max | Mean |
|---|
| January | 1 | 5 | 3 |
|---|
| February | 1.1 | 5.9 | 3.5 |
|---|
| March | 3.1 | 9.7 | 6.4 |
|---|
| April | 5.8 | 14.4 | 10.1 |
|---|
| May | 9 | 18.1 | 13.6 |
|---|
| June | 12.2 | 21.2 | 16.7 |
|---|
| July | 14.3 | 23.5 | 18.9 |
|---|
| August | 14.2 | 23.2 | 18.7 |
|---|
| September | 11.3 | 19.1 | 15.2 |
|---|
| October | 8 | 14.3 | 11.1 |
|---|
| November | 4.7 | 9.1 | 6.9 |
|---|
| December | 1.9 | 5.6 | 3.7 |
|---|
| Year | 7.3 | 14.1 | 10.65 |
|---|
amounts to
795 millimeters per year: so, it is at an intermediate level. It ranges from
50 millimeters in the driest month (February) to
85 millimeters in the wettest one (July). Here is the average precipitation.
Dortmund - Average precipitation| Month | Days |
|---|
| January | 65 | 12 |
|---|
| February | 50 | 9 |
|---|
| March | 55 | 13 |
|---|
| April | 60 | 10 |
|---|
| May | 65 | 10 |
|---|
| June | 80 | 12 |
|---|
| July | 85 | 11 |
|---|
| August | 75 | 9 |
|---|
| September | 65 | 11 |
|---|
| October | 55 | 11 |
|---|
| November | 70 | 12 |
|---|
| December | 75 | 13 |
|---|
| Year | 795 | 133 |
|---|
There are on average around 1590
sunshine hours per year. Here are the average hours of sunshine per day.
Dortmund - Sunshine hours| Month | Average | Total |
|---|
| January | 2 | 55 |
|---|
| February | 2.5 | 75 |
|---|
| March | 4 | 125 |
|---|
| April | 5.5 | 170 |
|---|
| May | 6.5 | 200 |
|---|
| June | 6.5 | 200 |
|---|
| July | 6.5 | 210 |
|---|
| August | 6 | 190 |
|---|
| September | 5 | 145 |
|---|
| October | 3.5 | 110 |
|---|
| November | 2 | 60 |
|---|
| December | 1.5 | 45 |
|---|
| Year | 4.4 | 1590 |
|---|
Dortmund - Weather by month
Based on the period 1991-2020
January, the coldest month of the year, is generally a cold month. The average temperature is of
3 °C, with a minimum of
1 °C and a maximum of
5 °C.
On the coldest nights of the month, the temperature usually drops to around
-7.5 °C. However, it dropped to
-17 °C in January 1997.
On the warmest days of the month, the temperature usually reaches around
12 °C. However, it reached
16 °C in January 1999.
Precipitation amounts to
65 mm, distributed over 12 days.
The day lasts on average 8 hours and 25 minutes.
There are on average 2 hours of sunshine per day. So, the sun shines 21% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
18.3 kph.
February is generally a cold month. The average temperature is of
3.5 °C, with a minimum of
1.1 °C and a maximum of
5.9 °C.
On the coldest nights of the month, the temperature usually drops to around
-6.5 °C. However, it dropped to
-15 °C in February 2012.
On the warmest days of the month, the temperature usually reaches around
13.5 °C. However, it reached
20 °C in February 2019.
Precipitation amounts to
50 mm, distributed over 9 days.
The day lasts on average 10 hours and 0 minutes.
There are on average 2.5 hours of sunshine per day. So, the sun shines 26% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is of
17.7 kph.
March is generally a quite cold month. The average temperature is of
6.4 °C, with a minimum of
3.1 °C and a maximum of
9.7 °C.
On the coldest nights of the month, the temperature usually drops to around
-3.5 °C. However, it dropped to
-10 °C in March 2010.
On the warmest days of the month, the temperature usually reaches around
18 °C. However, it reached
23 °C in March 1998.
Precipitation amounts to
55 mm, distributed over 13 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 34% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
16.9 kph.
April is generally a mild month. The average temperature is of
10.1 °C, with a minimum of
5.8 °C and a maximum of
14.4 °C.
On the coldest nights of the month, the temperature usually drops to around
-1 °C. However, it dropped to
-6 °C in April 1996.
On the warmest days of the month, the temperature usually reaches around
23 °C. However, it reached
27 °C in April 2007.
Precipitation amounts to
60 mm, distributed over 10 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 40% of the time.
The average humidity is 64%.
The average wind speed is of
14.5 kph.
May is generally a mild month. The average temperature is of
13.6 °C, with a minimum of
9 °C and a maximum of
18.1 °C.
On the coldest nights of the month, the temperature usually drops to around
2.5 °C. However, it dropped to
-1 °C in May 2011.
On the warmest days of the month, the temperature usually reaches around
26.5 °C. However, it reached
32 °C in May 2005.
Precipitation amounts to
65 mm, distributed over 10 days.
The day lasts on average 15 hours and 40 minutes. So the days are long.
There are on average 6.5 hours of sunshine per day. So, the sun shines 41% of the time.
The average humidity is 65%.
The average wind speed is of
13.8 kph.
June is generally a very mild month. The average temperature is of
16.7 °C, with a minimum of
12.2 °C and a maximum of
21.2 °C.
On the coldest nights of the month, the temperature usually drops to around
7 °C. However, it dropped to
3 °C in June 2009.
On the warmest days of the month, the temperature usually reaches around
30.5 °C. However, it reached
36 °C in June 2019.
Precipitation amounts to
80 mm, distributed over 12 days.
The day lasts on average 16 hours and 35 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 6.5 hours of sunshine per day. So, the sun shines 40% of the time.
The average humidity is 66%.
The average wind speed is of
13.4 kph.
July, the warmest month of the year, is generally a warm month. The average temperature is of
18.9 °C, with a minimum of
14.3 °C and a maximum of
23.5 °C.
On the coldest nights of the month, the temperature usually drops to around
9.5 °C. However, it dropped to
6 °C in July 2015.
On the warmest days of the month, the temperature usually reaches around
32 °C. However, it reached
39 °C in July 2019.
Precipitation amounts to
85 mm, distributed over 11 days.
The day lasts on average 16 hours and 5 minutes. So the days are long.
There are on average 6.5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 65%.
The average wind speed is of
13.5 kph.
August is generally a warm month. The average temperature is of
18.7 °C, with a minimum of
14.2 °C and a maximum of
23.2 °C.
On the coldest nights of the month, the temperature usually drops to around
9 °C. However, it dropped to
6 °C in August 2014.
On the warmest days of the month, the temperature usually reaches around
31.5 °C. However, it reached
37 °C in August 2003.
Precipitation amounts to
75 mm, distributed over 9 days.
The day lasts on average 14 hours and 30 minutes. So the days are long.
There are on average 6 hours of sunshine per day. So, the sun shines 43% of the time.
The average humidity is 65%.
The average wind speed is of
13.4 kph.
September is generally a very mild month. The average temperature is of
15.2 °C, with a minimum of
11.3 °C and a maximum of
19.1 °C.
On the coldest nights of the month, the temperature usually drops to around
6 °C. However, it dropped to
2 °C in September 2018.
On the warmest days of the month, the temperature usually reaches around
26.5 °C. However, it reached
32 °C in September 2013.
Precipitation amounts to
65 mm, distributed over 11 days.
The day lasts on average 12 hours and 35 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 39% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is of
13.6 kph.
October is generally a mild month. The average temperature is of
11.1 °C, with a minimum of
8 °C and a maximum of
14.3 °C.
On the coldest nights of the month, the temperature usually drops to around
1 °C. However, it dropped to
-5 °C in October 2003.
On the warmest days of the month, the temperature usually reaches around
21.5 °C. However, it reached
28 °C in October 2018.
Precipitation amounts to
55 mm, distributed over 11 days.
The day lasts on average 10 hours and 35 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 34% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is of
15.4 kph.
November is generally a quite mild month. The average temperature is of
6.9 °C, with a minimum of
4.7 °C and a maximum of
9.1 °C.
On the coldest nights of the month, the temperature usually drops to around
-2 °C. However, it dropped to
-7 °C in November 1993.
On the warmest days of the month, the temperature usually reaches around
16 °C. However, it reached
21 °C in November 2014.
Precipitation amounts to
70 mm, distributed over 12 days.
The day lasts on average 8 hours and 50 minutes.
There are on average 2 hours of sunshine per day. So, the sun shines 23% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
16 kph.
December is generally a cold month. The average temperature is of
3.7 °C, with a minimum of
1.9 °C and a maximum of
5.6 °C.
On the coldest nights of the month, the temperature usually drops to around
-6 °C. However, it dropped to
-15 °C in December 1996.
On the warmest days of the month, the temperature usually reaches around
12 °C. However, it reached
16 °C in December 2019.
Precipitation amounts to
75 mm, distributed over 13 days.
The day lasts on average 7 hours and 55 minutes. So the days are short. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 1.5 hours of sunshine per day. So, the sun shines 19% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is of
17.9 kph.