Climate and monthly weather forecastPortorož, Slovenia

The climate of Portorož

Situated on Slovenia's Adriatic Sea coast, Portorož boasts a climate that is often classified as Cfb or a marine west coast, warm summer climate according to the Köppen climate classification. This unique climate combination arises due to the town's strategic geographic location, influenced by maritime and continental weather patterns.

Analyzing the annual weather parameters, a pattern of moderate temperature changes becomes evident. The overall weather during the year is relatively mild, marked by moderate winter temperatures and warm but bearable summer temperatures.

Focusing on the specifics of weather parameters, the highest average high temperature climbs to 28.4°C (83.1°F) in July, while the lowest average low temperature drops to 0.4°C (32.7°F) in February. The rainfall appears to be most significant from September to November, with the heaviest shower round reaching 124mm (4.88") in September. Days with rainfall are pretty consistent throughout the year, fluctuating from 7.5 days in February to 11 days in May.

The best time to visit Portorož

The most enjoyable time to visit Portorož is arguably between May and September when the average high temperatures range from 21.8°C (71.2°F) to 28.4°C (83.1°F). These months also bring forth the highest average sea temperatures, from 18°C (64.4°F) in May, peaking at 24.8°C (76.6°F) in July and August, and declining to 23.3°C (73.9°F) in September. Despite a higher probability of rain in this period, a burst of plentiful sunshine ensures pleasant conditions. The many bright hours during this period, reaching a peak of 10.2 sunshine hours in July, compensate well for the occasional showers.

The worst time to visit Portorož

On the far end of the spectrum, from December to February, Portorož experiences the coldest temperatures of the year. The average high temperatures during these months range from 8.6°C (47.5°F) to 9.7°C (49.5°F). The sea temperature also significantly decreases, reaching a low of 9.3°C (48.7°F) in February. While daylight hours during this time dip to their shortest, with 8.8 hours in December, the sunshine hours also decline to the lowest, showing only 3 hours in December and February. Thus, it might be prudent to avoid these cold, less sunny months.

Spring weather in Portorož

Spring in Portorož features a gradual increase in temperatures, from an average high of 13.1°C (55.6°F) in March to 21.8°C (71.2°F) in May. The average low-temperature range for spring falls from 3.1°C (37.6°F) to 11°C (51.8°F). A steady rise in sea temperature from 10.1°C (50.2°F) to 18°C (64.4°F) occurs simultaneously with this warm-up on land. Despite a slight increase in rainfall, daylight increases, and higher UV indexes in the spring welcome visitors with open arms.

Summer weather in Portorož

Summers in Portorož are warm and comfortable with temperatures averaging between 21.8°C (71.2°F) and 28.4°C (83.1°F). The lowest average temperature during this season is around 14.5°C (58.1°F) in June. Sea temperatures peak to a comfortable 24.8°C (76.6°F) in July and August, perfect for water-based activities. Although rainfall is relatively higher, with a peak of 86mm (3.39") in June, the abundant sunlight balances the weather conditions.

Autumn weather in Portorož

Autumn sees a progressive drop in temperature, ranging from an average high of 23.9°C (75°F) in September to 13.2°C (55.8°F) by November. Similarly, the average low temperature drops from 13°C (55.4°F) to 4.7°C (40.5°F). Although the sea temperature remains warm in early autumn, it slowly cools down, reaching 16.1°C (61°F) by November. Rainfall becomes significantly high during this season, making it slightly less preferable for tourism.

Winter weather in Portorož

The cold air rolls into Portorož in winter with average high temperatures plummeting to a range from 8.6°C (47.5°F) to 9.7°C (49.5°F) from December to February. The average low temperature hovers between 0.6°C (33.1°F) and 1.4°C (34.5°F) during this period, making it the chilliest time of the year. The sea temperature also takes a chilly dip, reaching its lowest at 9.3°C (48.7°F) in February. In these months, the duration of daylight and sunshine hours are at their shortest, speaking to the town's true winter character. Despite this, rainfall decreases and the relative air humidity settles at a comfortable midpoint, offering a spark of warmth in the cold months.

Weather in January

Sitting at winter's core, January brings chilly days to Portorož. Compared to December, daytime temperatures reach up to 8.6°C (47.5°F) whilst the nighttime temperatures plummet down to a frigid 0.6°C (33.1°F). With cold temperatures, it is imperative to bring heavy clothing. Weather in January »

Weather in February

February witnesses a slight rise in temperatures compared to January, bringing a bit more comfort for those who find January's chilliness a bit too cold. Cold winds still blow across Portorož but it is the month with the lowest rainfall, considering a total precipitation of 47mm (1.85") compared to other winter months. Weather in February »

Weather in March

March announces the start of Spring in Portorož, with the weather gradually warming up. The increase in temperature to a welcoming 13.1°C (55.6°F) during the day and an overnight low of 3.1°C (37.6°F) marks the departure from the winter chill. Weather in March »

Weather in April

April exhibits a further rise in temperature, but it is the increase in rainfall to 65mm (2.56") that characterizes this month’s weather in Portorož. It's a month to brace for intermittent showers while enjoying the increased sunlight hours. Weather in April »

Weather in May

May serves as a prelude to the summer season in Portorož with daily temperatures soaring to a comfortable 21.8°C (71.2°F). It's a time of predominantly clear skies with increased daylight making it suitable for outdoor enthusiasts. Weather in May »

Weather in June

June is the harbinger of summer in Portorož, boasting about the year’s highest sea temperatures, reaching 22.8°C (73°F), inviting beach enthusiasts into the water. The pleasant weather conditions continue throughout the month despite the variables of rain and humidity. Weather in June »

Weather in July

July basks in the heart of summer with scorching heat across Portorož, marking the highest temperature spike hitting 28.4°C (83.1°F). Despite the heat, the city enjoys the year's highest average sunlight with 10.2 hours a day. The summer weather prompts visitors to dip into the cool sea water, as the beach season hits full swing. Weather in July »

Weather in August

In August, Portorož continues to experience high summer heat with temperatures closely mirroring those of July. In spite of being one of the hottest months, it’s traced with frequent rainfall, averaging about 78mm (3.07"). It's a peak season for tourists, so expect busy streets, full hotels, and populated beaches. Weather in August »

Weather in September

September marks the departure of summer with the onset of cooler autumn conditions. The rainfall jumps to its yearly peak at 124mm (4.88"), dipping temperatures a considerable margin. You can notice the daylight hours and sunshine slowly decreasing as the autumn progresses. Weather in September »

Weather in October

October intensifies the arrival of autumn in Portorož, reinforcing the conditions set by September. As temperatures begin to get cooler, fall foliage starts to spring around the city. Despite a higher monthly average rainfall than September, October still caters to outdoor activities. Weather in October »

Weather in November

November hosts the fall's finale with a rapid decrease in temperatures, sliding to 4.7°C (40.5°F) in the nights. The daylight hours are noticeably shorter, coupled with cooler temperatures pointing towards the approaching winter. Weather in November »

Weather in December

December, with temperatures dropping to 1.4°C (34.5°F) at night, signals the commencement of winter in Portorož. It's a month of minimal sunlight hours, making it the year’s darkest with the least average sunshine. With a significant dip in sea temperature, swimming activities take a back seat for the majority. Weather in December »