The city is located on the northern coast of Portugal, on the estuary of the Douro River.
blows frequently: in the cold half-year, it is caused by Atlantic depressions, and can be strong, while in summer, a cool breeze from the sea blows in the afternoon.
of the coldest month (January) is of 10.2 °C (50.3 °F), that of the warmest month (August) is of 19.9 °C (67.7 °F).
is quite abundant, in fact, it amounts to 1,255 millimeters (49.4 inches) per year. The rains are frequent from October to May, while from June to September it rains quite rarely, and very rarely in July and August.
, from December to February, is mild: daytime temperatures hover around 14/15 °C (57/59 °F). The rains occur in periods of bad weather, which last a few days, and may be abundant.
Compared to Lisbon, cold days are more likely, while snow is hardly ever seen. The last snowfall of some importance occurred in February 1983.
On the coldest nights of the year, the temperature typically drops to around 0 °C (32 °F). The coldest record is -4 °C (25 °F), recorded in January 1941. More recently, the temperature dropped to -3.5 °C (25.5 °F) in February 1983.
, from March to May, is cool; episodes of bad weather and wind are still quite frequent, but there are also sunny periods, with mild temperatures. In May, the maximum temperature is on average about 20 °C (68 °F).
, from June to mid-September, is mild or pleasantly warm. In fact, there are quite cool periods, with highs around 20/23 °C (68/73 °F), and sometimes even lower in June, and warmer periods, with temperatures hovering between 26 °C and 30 °C (79 and 86 °F).
Sometimes, from mid-June to early September, heat waves can occur, usually of short duration, in which the temperature can reach 38/39 °C (100/102 °F), as happened in August 2003 or in July 2013. However, this happens less often than in south-central Portugal.
In summer, the weather is usually good, but some Atlantic fronts bringing clouds and rain can not be excluded, especially in June, which, to tell the truth, often resembles a spring month.
, from mid-September to November, is mild, and becomes gradually wetter over the weeks, although good weather often continues until mid-October.
in Porto is very good in summer, when sunny days prevail (though a little less than in central and southern Portugal). In the other seasons, Atlantic depressions able to bring wind and rain are frequent, although there are also sunny days. However, there are on average 2,500 hours of sunshine per year.
near Porto is cold to swim in: the water temperature reaches 18.5 °C (65 °F) in July and September, and 19 °C (66 °F) in August.
to visit Porto runs from June to September, since it is the warmest and the least rainy period of the year. July and August are the warmest months, but the heat is rarely excessive, and in addition, they are the least rainy. However, in September too, the rains are still quite rare. In May, you can go, but cool and rainy days are more frequent.
Even in summer, it's better to bring a sweatshirt, and maybe a light jacket for the evening.
Those who want to avoid hot periods (which are quite rare, but possible) can choose the period from early May to mid-June and from mid-September to early October, although it rains more often.
. Here are the average temperatures.
January, the coldest month of the year, is generally a mild month. The average temperature is of
10.2 °C, with a minimum of
6.3 °C and a maximum of
14.1 °C.

On the coldest nights of the month, the temperature usually drops to around
0.5 °C. However, it dropped to
-2 °C in January 2003.

On the warmest days of the month, the temperature usually reaches around
18.5 °C. However, it reached
22.2 °C in January 2016.

Precipitation amounts to
160 mm, distributed over 13 days.
The day lasts on average 9 hours and 35 minutes.

There are on average 4 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is of
11.4 kph.

The average sea temperature is of
14.3 °C. Therefore, the sea is very cold for swimming.
February is generally a mild month. The average temperature is of
10.7 °C, with a minimum of
6.4 °C and a maximum of
15.1 °C.

On the coldest nights of the month, the temperature usually drops to around
0.5 °C. However, it dropped to
-2 °C in February 1991.

On the warmest days of the month, the temperature usually reaches around
20 °C. However, it reached
24 °C in February 2019.

Precipitation amounts to
140 mm, distributed over 12 days.
The day lasts on average 10 hours and 40 minutes.

There are on average 4.5 hours of sunshine per day. So, the sun shines 43% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is of
10.9 kph.

The average sea temperature is of
13.8 °C. Therefore, the sea is very cold for swimming.
March is generally a mild month. The average temperature is of
12.6 °C, with a minimum of
8.1 °C and a maximum of
17.1 °C.

On the coldest nights of the month, the temperature usually drops to around
2 °C. However, it dropped to
-2.1 °C in March 2005.

On the warmest days of the month, the temperature usually reaches around
24 °C. However, it reached
29.1 °C in March 2002.

Precipitation amounts to
90 mm, distributed over 10 days.
The day lasts on average 12 hours and 0 minutes.

There are on average 6 hours of sunshine per day. So, the sun shines 52% of the time.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is of
11.7 kph.

The average sea temperature is of
13.8 °C. Therefore, the sea is very cold for swimming.
April is generally a mild month. The average temperature is of
13.7 °C, with a minimum of
9.4 °C and a maximum of
18.1 °C.

On the coldest nights of the month, the temperature usually drops to around
4 °C. However, it dropped to
1 °C in April 1995.

On the warmest days of the month, the temperature usually reaches around
25.5 °C. However, it reached
31.2 °C in April 1997.

Precipitation amounts to
115 mm, distributed over 11 days.
The day lasts on average 13 hours and 25 minutes.

There are on average 7 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 76%. Hence, the air is normally humid.
The average wind speed is of
11.5 kph.

The average sea temperature is of
14.4 °C. Therefore, the sea is very cold for swimming.
May is generally a very mild month. The average temperature is of
16 °C, with a minimum of
11.7 °C and a maximum of
20.4 °C.

On the coldest nights of the month, the temperature usually drops to around
6.5 °C. However, it dropped to
3.8 °C in May 1991.

On the warmest days of the month, the temperature usually reaches around
29.5 °C. However, it reached
34 °C in May 2006.

Precipitation amounts to
100 mm, distributed over 10 days.
The day lasts on average 14 hours and 30 minutes. So the days are long.

There are on average 8.5 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 76%. Hence, the air is normally humid.
The average wind speed is of
11.4 kph.

The average sea temperature is of
15.5 °C. Therefore, the sea is cold for swimming.
June is generally a warm month. The average temperature is of
18.2 °C, with a minimum of
13.8 °C and a maximum of
22.6 °C.

On the coldest nights of the month, the temperature usually drops to around
9.5 °C. However, it dropped to
7 °C in June 1993.

On the warmest days of the month, the temperature usually reaches around
32 °C. However, it reached
39 °C in June 2003.

Precipitation amounts to
45 mm, distributed over 6 days.
The day lasts on average 15 hours and 5 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 9 hours of sunshine per day. So, the sun shines 61% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is of
10.5 kph.

The average sea temperature is of
17.2 °C. Therefore, the sea is cold for swimming.
July is generally a warm month. The average temperature is of
19.5 °C, with a minimum of
14.9 °C and a maximum of
24.2 °C.

On the coldest nights of the month, the temperature usually drops to around
11 °C. However, it dropped to
9 °C in July 1993.

On the warmest days of the month, the temperature usually reaches around
33.5 °C. However, it reached
38 °C in July 1993.

Precipitation amounts to
20 mm, distributed over 3 days.
The day lasts on average 14 hours and 50 minutes. So the days are long.

There are on average 10 hours of sunshine per day. So, the sun shines 67% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is of
10 kph.

The average sea temperature is of
18.3 °C. Therefore, the sea is very cool for swimming.
August, the warmest month of the year, is generally a warm month. The average temperature is of
19.9 °C, with a minimum of
15 °C and a maximum of
24.8 °C.

On the coldest nights of the month, the temperature usually drops to around
10.5 °C. However, it dropped to
9.7 °C in August 2002.

On the warmest days of the month, the temperature usually reaches around
33 °C. However, it reached
39 °C in August 2003.

Precipitation amounts to
25 mm, distributed over 3 days.
The day lasts on average 13 hours and 40 minutes.

There are on average 9.5 hours of sunshine per day. So, the sun shines 70% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is of
9.3 kph.

The average sea temperature is of
18.9 °C. Therefore, the sea is very cool for swimming.
September is generally a warm month. The average temperature is of
18.8 °C, with a minimum of
14 °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
8.5 °C in September 1999.

On the warmest days of the month, the temperature usually reaches around
31.5 °C. However, it reached
37.4 °C in September 2018.

Precipitation amounts to
70 mm, distributed over 6 days.
The day lasts on average 12 hours and 25 minutes.

There are on average 7.5 hours of sunshine per day. So, the sun shines 60% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is of
8.9 kph.

The average sea temperature is of
18.5 °C. Therefore, the sea is very cool for swimming.
October is generally a very mild month. The average temperature is of
16.5 °C, with a minimum of
12.2 °C and a maximum of
20.8 °C.

On the coldest nights of the month, the temperature usually drops to around
7 °C. However, it dropped to
3 °C in October 2018.

On the warmest days of the month, the temperature usually reaches around
27.5 °C. However, it reached
33.1 °C in October 2011.

Precipitation amounts to
140 mm, distributed over 11 days.
The day lasts on average 11 hours and 5 minutes.

There are on average 6 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is of
10.6 kph.

The average sea temperature is of
17.5 °C. Therefore, the sea is cold for swimming.
November is generally a mild month. The average temperature is of
13 °C, with a minimum of
9 °C and a maximum of
16.9 °C.

On the coldest nights of the month, the temperature usually drops to around
3 °C. However, it dropped to
0 °C in November 2000.

On the warmest days of the month, the temperature usually reaches around
22.5 °C. However, it reached
26 °C in November 2007.

Precipitation amounts to
160 mm, distributed over 12 days.
The day lasts on average 9 hours and 55 minutes.

There are on average 4.5 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
10.8 kph.

The average sea temperature is of
16.3 °C. Therefore, the sea is cold for swimming.
December is generally a mild month. The average temperature is of
11 °C, with a minimum of
7.3 °C and a maximum of
14.8 °C.

On the coldest nights of the month, the temperature usually drops to around
1 °C. However, it dropped to
-2 °C in December 2014.

On the warmest days of the month, the temperature usually reaches around
19 °C. However, it reached
22 °C in December 2015.

Precipitation amounts to
195 mm, distributed over 13 days.
The day lasts on average 9 hours and 20 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.

There are on average 4 hours of sunshine per day. So, the sun shines 43% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
11.6 kph.

The average sea temperature is of
15.1 °C. Therefore, the sea is cold for swimming.