Climate and monthly weather forecast
Lisbon, Portugal

In the city of Lisbon, Portugal, the prevailing climate is identified as Mediterranean hot summer, as indicated by the Köppen climate classification (Csa). Characterised by warm to hot, dry summers and mild to cool, wet winters, this climate type is reflective of Lisbon's prime geographical positioning with respect to the Atlantic Ocean.

Assessing the climatological parameters recorded for the region, it is observable that temperatures fluctuate between 8.3°C to 28.3°C throughout the year. The burgeoning warmth of spring transitions into the sultry heat of summer, with the months from June to August experiencing the year's peak temperatures, reaching up to 28.3°C. Conversely, the cooler months from December to February offer a respite from this heat, with temperatures dropping to a cooler range of between 8.3°C and 15.3°C.

Rainfall predominantly takes place during the colder months, with November and December receiving the highest amounts, amassing 128mm and 127mm, respectively. On the contrary, the hot, dry summer months from July to August experience almost negligible rainfall, recording only 4mm and 6mm respectively during this period. The number of rainfall days follows a similar pattern, with an increased frequency observed during the wetter months.

As for Lisbon's sunshine and UV index, the two are interconnected. The city relishes in up to 11 hours of sunshine from June to August, coinciding with a high UV index of 9. These factors diminish as winter nears, with a decrease in daylight hours and a corresponding drop in the UV index to 2 by December.

For those planning a trip to Lisbon, the city's favourable climate lends itself to tourism throughout most of the year. However, if warm weather and long days are desired, the ideal period to visit is between early June and late August. During this timeframe, temperatures peak between 25.7°C and 28.3°C, the sea temperature averages 18.9°C to 19.6°C, and daylight extends up to 14.8 hours per day. The UV index is at its highest, as are the hours of sunshine, ensuring optimal conditions for outdoor activities.

Visitors may prefer to avoid Lisbon during November and December when the city experiences its maximum rainfall, measuring 128mm and 127mm, respectively. These months also hold a record for the highest number of rainfall days, limiting outdoor activities. Though the temperatures during this period range from 9.4°C to 15.3°C, the shorter daylight hours and the lower amount of sunshine, coming down to five hours per day, may not be ideal for social exploration or activities.

The spring months in Lisbon, extending from March to May, herald a significant change in weather patterns. The temperatures rise from a mild 14.8°C in March to a warmer 22.1°C by May. Concurrently, rainfall decreases over these months, from 53mm to 54mm, while the number of daylight hours increases from 12.0 to an impressive 14.3. Moreover, the spring season sees a growth in the amount of daily sunshine and UV index, displaying a gentle rise through the period.

Summer in Lisbon, lasting from June to August, is characterised by soaring temperatures, lengthening daylight hours, and a noticeable decline in rainfall. The months of July and August mark the highest temperatures of the year, averaging between 28.2°C and 28.3°C. Rainfall is minimal, recording just 4mm and 6mm, and the sea warms up to an appealing 18.9°C to 19.6°C. Consequently, the UV index reaches its peak at 9, mirroring the high volume of sunshine that endures for up to 11 hours per day.

Autumn in Lisbon, which runs from September to November, displays a gradual lowering of the temperature and an increase in rainfall. Temperatures steadily transition from a warm 26.5°C in September to a cooler 18.2°C by November. Rainfall, simultaneously, rises from 33mm to a substantial 128mm in November. While daylight hours and the amount of sunshine decrease over this season, the UV index follows a steady downward trend, beginning at 6 and ending at 3 by November's end.

Winter in Lisbon, from December to February, brings lower temperatures and increased rainfall. During these months, the temperatures hover between 8.3°C and 15.3°C while rainfall peaks in December with 127mm accompanied by the highest number of rainfall days. With shorter daylight hours and reduced sunshine, it is noteworthy that the UV index also drops to its lowest yearly average of 2. Despite the colder climate, the city remains relatively mild compared to other European regions, maintaining sea temperatures between 15.8°C to 16.6°C.

Starting the year off, January in Lisbon, Portugal, typically experiences chillier temperatures, a cloudy sky, and frequent rainfall. This is the time when Lisbon sees the highest rainfall of the year, with an average of 100mm recorded. Weather in January »

Moving into February, the weather in Lisbon starts showing the first signs of transition from winter to spring. The temperature sees a slight increase from January, however, rainfall remains frequent with an average of 14 days of downpours. Weather in February »

Transitioning towards spring, March in Lisbon brings a new sense of vitality to the city’s weather. There is a clear surge in the temperature, with the maximum rising to 18.8°C. This month marks one of the most significant diversions from winter, with the rainfall not only decreasing, but the city also enjoying more hours of daylight. Weather in March »

April exhibits renowned spring weather in Lisbon, marked by stretch in the daylight hours. The increase in sunshine showcases the city in a beautiful light, despite the occurrence of rainfall increasing to 68mm. Average sea temperatures continue with their steady climb, pushing towards the warmer end of spectrum. Weather in April »

The arrival of May marks the onset of the city’s summer season. Despite the rainfall decreasing to 54mm in May, sporadic showers continue to maintain Lisbon’s lush landscapes. Gradually, the city begins to warm up with temperature highs moving past the 20°C mark. Weather in May »

June brings forth perfect summer weather in Lisbon. The city experiences a drastic drop in rainfall, reducing to a mere average of 16mm. This significant reduction is matched with an almost equal increase in temperatures, setting the right mood for sunbathing on the coastal beaches. Weather in June »

July is the epitome of summer in Lisbon. The city records the highest temperature of the year, reaching an average peak of 28.2°C. Even though the city experiences a minimal amount of rain, it does not deter visitors from flocking to the beaches to enjoy the warm sea temperatures. Weather in July »

Riding the wave of summer, August in Lisbon continues with conditions similar to July. With the temperature reaching a peak of 28.3°C, this is the only month to rival July in terms of warmth. The rain remains a scarce occurrence, and tourists can enjoy clear blue skies above. Weather in August »

September sees a subtle shift in weather patterns in Lisbon, marking the beginning of the cooling down process. Despite the average temperature falling to 26.5°C, the sun continues to shine bright, albeit for fewer hours. Though the city experiences marginally more rainfall than the previous month, the weather remains conducive for outdoor activities. Weather in September »

October in Lisbon bears witness to the onset of autumn, with temperatures gradually declining. As the city braces for winter, rainfall frequency increases, with an average precipitation of 101mm. Despite this, Lisbon retains its charm, with alternating periods of sun and showers. Weather in October »

November is characterized by a noticeable shift in Lisbon’s weather as winter approaches. The temperatures drop further, signaling the city to brace for the chilly winds of December. Rainfall reaches its second-highest volume of the year, recording an average of 128mm. Weather in November »

During December, Lisbon finally succumbs to winter, with temperatures hitting near-year lows at around 15.3°C. Despite experiencing substantial rainfall at 127mm, Lisbon retains its charm, morphing into a winter wonderland under the Mediterranean sun. Weather in December »