Climate and monthly weather forecastPorto, Portugal

The climate of Porto

Sitting along the Douro River in northwest Portugal, Porto enjoys a Mediterranean climate, more specifically defined as a warm summer Mediterranean climate under the Köppen climate classification, marked by hot, dry summers and mild, wet winters. The climate shifts subtly throughout the year, with changes most noticeable in temperature and rainfall patterns.

Temperature highs in Porto range mildly from 13.8°C (56.8°F) in January to a pleasant 25.7°C (78.3°F) in August. Likewise, low temperatures are relatively consistent, starting from 5.2°C (41.4°F) in January to a highest low of 15.9°C (60.6°F) in both July and August.

Rainfall in Porto tends to be heaviest from October to January, with the most being recorded in December at 181mm (7.13"). In contrast, summer months from June to August see a significant decrease in precipitation, with the driest month being July with an average rainfall of 20mm (0.79").

UV index levels are highest from June to August, reaching a top index of 8. Winters offer more comfort from the sun with UV index dwindling to 1 in December.

The best time to visit Porto

Considering Porto’s overall climate and weather data, the best time to visit Porto would be from May to September. During these months, the city experiences ample sunshine hours, ranging from 7.2 hours in April to a peak of 9.9 hours in July. Sea temperatures also become inviting during these months, starting off from a warm 16.5°C (61.7°F) in May and reaching a luxurious 18.2°C (64.8°F) in September. This is coupled with a low level of rainfall, ranging from just 40mm (1.57") in June to a still considerable 90mm (3.54") in May.

The worst time to visit Porto

Although Porto doesn’t experience harsh weather extremes, travelers might want to avoid the city in the wintertime, primarily between November and February. Rainfall during these months is high, exceeding 150mm (5.91") from November to December. Furthermore, sea temperatures moderately drop to between 14.3°C (57.7°F) to 15.6°C (60.1°F) and daylight hours fall to as few as 9 hours in December. During these months, sunshine hours also decrease to between 4 to 4.6 hours per day.

Spring weather in Porto

Spring weather in Porto is quite inviting for outdoor activities. Average highs gradually escalate from 15°C (59°F) in February to 20.1°C (68.2°F) by May. Similarly, the lows gently climb from 5.9°C (42.6°F) in February to 11.6°C (52.9°F) in May. Rainfall drops progressively from 111mm (4.37") in February to about 90mm (3.54") in May. In this transitional season, sunshine hours begin to increase, reaching an average of 8.3 hours per day by May with daylight lasting for up to 14.5 hours.

Summer weather in Porto

In summer, Porto enjoys average highs from 23.5°C (74.3°F) in June to 25.7°C (78.3°F) in August. Corresponding lows are comfortably mild, starting from 14.5°C (58.1°F) in June and reaching 15.9°C (60.6°F) in July and August. Rainfall during the summer drastically decrease to its annual lowest, with July receiving barely a drizzle at 20mm (0.79"). June, July, and August respectively record daylight hours of 15.1, 14.8, and 13.8 making this season the best for outdoor activities.

Autumn weather in Porto

Autumn brings a decrease in average high temperatures, from 24.1°C (75.4°F) in September to 17.1°C (62.8°F) in November. Lows also drop from 14.7°C (58.5°F) to 8.9°C (48°F) within the same period. Rainfall starts to pick up from 72mm (2.83") in September to 172mm (6.77") by November, marking the start of Porto's wet season. All the while, daylight hours reduce from 12.5 in September to barely 10 hours in November.

Winter weather in Porto

Winter provides cooler temperatures in Porto, with highs varying from 14.4°C (57.9°F) in December to 13.8°C (56.8°F) in January, and lows fluctuating between 6.9°C (44.4°F) in December and just 5.2°C (41.4°F) by January. Accompanied by the shortest daylight hours of the year, 9.3 to 9.6 hours, and minimal sunshine, winter marks a slower, more tranquil time in Porto. Rainfall peaks during this season, recording the annual maximum of 181mm (7.13") in December.

Weather in January

January in Porto, Portugal offers cool temperatures typical of the season. Compared to the milder conditions of December, this month sees a drop in average high and low temperatures to 13.8°C (56.8°F) and 5.2°C (41.4°F) respectively. Weather in January »

Weather in February

February in Porto presents a slight elevation in temperatures, a relief from the colder January. The rainfall volume lessens, giving way to a few additional hours of sun. With 111mm (4.37") of rainfall, it seems milder compared to the downpour experienced in January. Weather in February »

Weather in March

The transition from winter to spring begins in March in Porto. A tangible rise in temperature occurs, making this month warmer than February. However, the most pronounced change is in the longer daylight hours, presenting up to 12 hours of daylight. Weather in March »

Weather in April

April brings a welcomed change in Porto's weather conditions, with higher temperatures and decreased rainfall. The daytime high experiences a bump up from the March readings, reflecting the onset of warmer spring days. Longer sunshine hours and dwindling rainfall firmly establish the month's spring identity. Weather in April »

Weather in May

In May, Porto experiences a steady climb towards summer conditions. The mild temperatures of April give way to a noticeable increase in warmth. This month records a low rainfall of 90mm (3.54"), a dramatic decrease compared to the preceding months. Weather in May »

Weather in June

June marks the official onset of summer in Porto. There is a noticeable leap in average temperatures from the mild conditions in May. The amount of rainfall drops to a yearly low of 40mm (1.57"), indicating the arrival of the dry season. Weather in June »

Weather in July

July in Porto continues the city's summer pattern, with temperatures soaring to their peak. The temperature climbs from June levels to reach a high of 25.3°C (77.5°F). Sunny days are all but guaranteed with a scant 20mm (0.79") of rainfall. Weather in July »

Weather in August

August brings no relief from the intense summer heat in Porto, with temperatures edging slightly higher than in July. However, a slight increase in rainfall occurs, but with a mere 33mm (1.3"), it hardly dampens the summer spirit. Weather in August »

Weather in September

September in Porto presents a gentle transition into autumn. A modest decrease in maximum temperatures occurs from the peak readings in August. Yet, it's worth noting that the month receives a higher rainfall of 72mm (2.83"), heralding the onset of the wetter period. Weather in September »

Weather in October

October brings a significant change in Porto's weather. The mild temperatures of September make way for a more pronounced decrease in warmth. Rainfall rises significantly to 158mm (6.22"), a stark jump from the previous month. The daylight hours wane noticeably as the city transitions towards winter. Weather in October »

Weather in November

In Porto, visiting in November means bracing for cooler temperatures. There's a dip in the average high and low temperatures from October down to 17.1°C (62.8°F) and 8.9°C (48°F). The bounteous rainfall of 172mm (6.77") signifies the approaching wettest stage of the year. Weather in November »

Weather in December

December brings the full-on winter chill to Porto. Falling temperatures mark a sharp contrast to the warmth experienced during the peak summer months. The month registers a high rainfall of 181mm (7.13"), making it the wettest month of the year. Weather in December »