Climate in Porto (Portugal)

In Porto, the climate is temperate oceanic, with mild, rainy winters and pleasantly warm, sunny summers.
The city is located on the northern coast of Portugal, on the estuary of the Douro River.
The wind 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.
During the night and in the early morning, in periods of good weather, fog can form all year round.
The average temperature 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).
Rainfall 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.



Winter, 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.

Spring, 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).

Summer, 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.

Autumn, from mid-September to November, is mild, and becomes gradually wetter over the weeks, although good weather often continues until mid-October.

The amount of sunshine 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.

The ocean 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.

Best Time

The best time 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.

Porto - Climate data

In Porto, the average temperature 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). Here are the average temperatures.
Precipitation amounts to 1255 millimeters (49.4 inches) per year: it is therefore quite abundant. It ranges from 20 mm (0.8 in) in the driest month (July) to 195 mm (7.7 in) in the wettest one (December). Here is the average precipitation.
The sea temperature ranges from 14 °C (57 °F) in February, March to
There are on average around 2470 sunshine hours per year. Here are the average hours of sunshine per day.

Porto - Weather by month

Based on the period 1991-2020

---

January, the coldest month of the year, is generally a mild month. The average temperature is of 10.2 °C (50 °F), with a minimum of 6.3 °C (43.3 °F) and a maximum of 14.1 °C (57.4 °F).
On the coldest nights of the month, the temperature usually drops to around 0.5 °C (33 °F). However, it dropped to -2 °C (28.4 °F) in January 2003.
On the warmest days of the month, the temperature usually reaches around 18.5 °C (65.5 °F). However, it reached 22.2 °C (72 °F) in January 2016.
Precipitation amounts to 160 mm (6.3 in), 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 11 kph (7 mph).
The average sea temperature is of 14.5 °C (57.5 °F). Therefore, the sea is very cold for swimming.

---

February is generally a mild month. The average temperature is of 10.7 °C (51 °F), with a minimum of 6.4 °C (43.4 °F) and a maximum of 15.1 °C (59.2 °F).
On the coldest nights of the month, the temperature usually drops to around 0.5 °C (33.5 °F). However, it dropped to -2 °C (28.4 °F) in February 1991.
On the warmest days of the month, the temperature usually reaches around 20 °C (68 °F). However, it reached 24 °C (75.2 °F) in February 2019.
Precipitation amounts to 140 mm (5.5 in), 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 11 kph (7 mph).
The average sea temperature is of 14 °C (57 °F). Therefore, the sea is very cold for swimming.

---

March is generally a mild month. The average temperature is of 12.6 °C (55 °F), with a minimum of 8.1 °C (46.5 °F) and a maximum of 17.1 °C (62.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 2 °C (36 °F). However, it dropped to -2.1 °C (28.2 °F) in March 2005.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 24 °C (75 °F). However, it reached 29.1 °C (84.4 °F) in March 2002.
Precipitation amounts to 90 mm (3.5 in), 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 12 kph (7 mph).
The average sea temperature is of 14 °C (57 °F). Therefore, the sea is very cold for swimming.

---

April is generally a mild month. The average temperature is of 13.7 °C (57 °F), with a minimum of 9.4 °C (48.8 °F) and a maximum of 18.1 °C (64.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 4 °C (39.5 °F). However, it dropped to 1 °C (33.8 °F) in April 1995.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 25.5 °C (78 °F). However, it reached 31.2 °C (88.2 °F) in April 1997.
Precipitation amounts to 115 mm (4.5 in), 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 12 kph (7 mph).
The average sea temperature is of 14.5 °C (58 °F). Therefore, the sea is very cold for swimming.

---

May is generally a very mild month. The average temperature is of 16 °C (61 °F), with a minimum of 11.7 °C (53.1 °F) and a maximum of 20.4 °C (68.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 6.5 °C (44 °F). However, it dropped to 3.8 °C (38.8 °F) in May 1991.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 29.5 °C (85.5 °F). However, it reached 34 °C (93.2 °F) in May 2006.
Precipitation amounts to 100 mm (3.9 in), 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 11 kph (7 mph).
The average sea temperature is of 15.5 °C (60 °F). Therefore, the sea is cold for swimming.

---

June is generally a warm month. The average temperature is of 18.2 °C (65 °F), with a minimum of 13.8 °C (56.9 °F) and a maximum of 22.6 °C (72.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 9.5 °C (49 °F). However, it dropped to 7 °C (44.6 °F) in June 1993.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 32 °C (90 °F). However, it reached 39 °C (102.2 °F) in June 2003.
Precipitation amounts to 45 mm (1.8 in), 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 10 kph (7 mph).
The average sea temperature is of 17 °C (63 °F). Therefore, the sea is cold for swimming.

---

July is generally a warm month. The average temperature is of 19.5 °C (67 °F), with a minimum of 14.9 °C (58.9 °F) and a maximum of 24.2 °C (75.5 °F).
On the coldest nights of the month, the temperature usually drops to around 11 °C (52 °F). However, it dropped to 9 °C (48.2 °F) in July 1993.
On the warmest days of the month, the temperature usually reaches around 33.5 °C (92.5 °F). However, it reached 38 °C (100.4 °F) in July 1993.
Precipitation amounts to 20 mm (0.8 in), 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 10 kph (6 mph).
The average sea temperature is of 18.5 °C (65 °F). 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 (68 °F), with a minimum of 15 °C (58.9 °F) and a maximum of 24.8 °C (76.6 °F).
On the coldest nights of the month, the temperature usually drops to around 10.5 °C (51 °F). However, it dropped to 9.7 °C (49.5 °F) in August 2002.
On the warmest days of the month, the temperature usually reaches around 33 °C (91 °F). However, it reached 39 °C (102.2 °F) in August 2003.
Precipitation amounts to 25 mm (1 in), 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 9 kph (6 mph).
The average sea temperature is of 19 °C (66 °F). Therefore, the sea is very cool for swimming.

---

September is generally a warm month. The average temperature is of 18.8 °C (66 °F), with a minimum of 14 °C (57.2 °F) and a maximum of 23.5 °C (74.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 9.5 °C (49 °F). However, it dropped to 8.5 °C (47.3 °F) in September 1999.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 31.5 °C (89 °F). However, it reached 37.4 °C (99.3 °F) in September 2018.
Precipitation amounts to 70 mm (2.8 in), 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 9 kph (6 mph).
The average sea temperature is of 18.5 °C (65.5 °F). Therefore, the sea is very cool for swimming.

---

October is generally a very mild month. The average temperature is of 16.5 °C (62 °F), with a minimum of 12.2 °C (54 °F) and a maximum of 20.8 °C (69.5 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 7 °C (44.5 °F). However, it dropped to 3 °C (37.4 °F) in October 2018.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 27.5 °C (81 °F). However, it reached 33.1 °C (91.6 °F) in October 2011.
Precipitation amounts to 140 mm (5.5 in), 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 11 kph (7 mph).
The average sea temperature is of 17.5 °C (63.5 °F). Therefore, the sea is cold for swimming.

---

November is generally a mild month. The average temperature is of 13 °C (55 °F), with a minimum of 9 °C (48.2 °F) and a maximum of 16.9 °C (62.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 3 °C (37.5 °F). However, it dropped to 0 °C (32 °F) in November 2000.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 22.5 °C (72.5 °F). However, it reached 26 °C (78.8 °F) in November 2007.
Precipitation amounts to 160 mm (6.3 in), 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 11 kph (7 mph).
The average sea temperature is of 16.5 °C (61.5 °F). Therefore, the sea is cold for swimming.

---

December is generally a mild month. The average temperature is of 11 °C (52 °F), with a minimum of 7.3 °C (45.1 °F) and a maximum of 14.8 °C (58.6 °F).
On the coldest nights of the month, the temperature usually drops to around 1 °C (34 °F). However, it dropped to -2 °C (28.4 °F) in December 2014.
On the warmest days of the month, the temperature usually reaches around 19 °C (66 °F). However, it reached 22 °C (71.6 °F) in December 2015.
Precipitation amounts to 195 mm (7.7 in), 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 12 kph (7 mph).
The average sea temperature is of 15 °C (59 °F). Therefore, the sea is cold for swimming.