Porto, Portugal's climate is quite hospitable, especially during the spring and summer months. Let's take a look at Porto's weather and climate to help guide you as you plan what to pack for your trip to Portugal and choose the best time of year to visit Portugal.
Porto has what is classified as a maritime climate, which basically means that it has warm summers and mild winters. Due to its position on the North Atlantic coast, cool ocean currents and northern trade winds keep the summers here from becoming overbearing, unlike the hotter summers found in Portugal's southern Alentejo and Algarve regions.
On average, June through September are the hottest months in Porto. On especially warm days, the temperature may reach the high 80s Fahrenheit, but it is generally closer to the mid 70s. Summer nighttime lows are generally in the 50s - not too chilly, but you should definitely bring a sweatshirt, just in case.
The coldest months in Porto are December through February, when overnight low temperatures can dip into the low 40s, and daily highs rarely crest 65 degrees. Spring and fall tend to feature highs in the low-to-mid 60s.
Porto summers are relatively precipitation-free; with June, July, and August each averaging less than 8 days of rain per month. The rainfall definitely ramps up during the fall and winter; December may get 17 or more rainy days during the month, with October, November, and February not far behind. Spring showers are common, but not as numerous or productive as those that take place during winter months.
The summer months in Porto offer visitors plenty of opportunities to get a suntan, with an average of 10 hours of sunshine per day during the peak season. The winter, however, is quite the opposite. During the months of December, January, and February, the sun may only show its face for 4 hours per day or less. Spring and fall are transitional periods that can be quite unpredictable. One day may be gorgeous, while the next day's weather is gloomy and stark.
Due to it's northern locale, the Atlantic waters off the coast of Porto can be quite chilly, even during the summer. While the southern coast of Portugal is warm enough to permit swimming year-round, Porto's beaches are definitely best experienced during the warmer months.
The busy season in Porto is definitely the summertime, but a great time can be had here nearly any time of year. The off-season has the perks of lower airfare and hotel rates, but sun lovers will probably find late April to mid-September to be the most pleasant time to visit.
More Travel Inspiration: Complete Portugal Travel Guide