May Weather in Portoroz, Slovenia

Last updated: August 27, 2025

May in Portorož, Slovenia showcases a delightful transition into warmer weather, with maximum temperatures reaching 24°C (76°F) and an average of 17°C (64°F), providing a pleasant backdrop for outdoor activities. Visitors can expect a range of temperatures, from a refreshing minimum of 10°C (50°F) during cooler nights. The month brings 105 mm (4.2 in) of precipitation over 13 days, contributing to the lush scenery that the region is known for. With an average humidity level of 70%, the air carries a gentle, refreshing quality, making May an ideal time to experience the beauty of this coastal gem.

May Temperature in Portoroz

In May, Portorož, Slovenia, welcomes the warmth of spring with mild temperatures that set a perfect backdrop for outdoor activities. With a minimum of 10°C (50°F) and a pleasant average of 17°C (64°F), the coastal town begins to shed the chill of winter, reaching delightful highs of 24°C (76°F). This upward trend in temperatures, starting from the cooler months of January through April, makes May an ideal time for visitors to enjoy the scenic beaches and vibrant local culture. As nature bursts into bloom, the temperate climate invites leisurely strolls along the promenade and explorations of the beautiful surrounding landscape, creating an enchanting atmosphere that truly captures the essence of spring in Slovenia.

May Weather in Portoroz: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Portoroz, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Portoroz, May typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec454749566373777871635649
Data source: Temperature data for Portoroz generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Portoroz

May in Portorož, Slovenia, marks a notable uptick in precipitation, with 105 mm (4.2 in) of rain falling over an average of 13 days. This increase aligns with the trend observed in previous spring months, where April recorded 86 mm (3.4 in) over 8 days. The flowing rains of May not only rejuvenate the lush landscapes but also hint at the wetter months ahead, as summer approaches. Compared to the lighter precipitation of 49 mm (1.9 in) observed in July, May’s abundant rainfall sets the stage for the changing seasons and the vibrant growth it fosters. As the weather transitions, residents and visitors alike can expect a lively atmosphere, underscored by the gentle rhythms of spring rain.

May Precipitation Trends in Portoroz

The chart displays monthly precipitation patterns in Portoroz, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Portoroz, May typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec581065786105684958171100183150
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Portoroz

In May, Portorož, Slovenia, experiences a notable transition in humidity levels, averaging around 70%. This represents a slight decrease from the preceding months of April and March, both of which recorded higher levels at 73% and 73% respectively. As spring unfolds, the coastal town begins to shed the heavier, moisture-laden air typical of winter, yet still maintains a comfortable level of humidity. This trend continues into June, where humidity drops further to 69%, signaling the onset of summer conditions. The gradual decline in humidity from winter's peak of 88% in January to May's more temperate levels not only enhances the pleasant coastal ambiance but also sets the stage for the dry and warm days that follow.

May Average Humidity in Portoroz

This chart illustrates the average monthly humidity levels in Portoroz, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Portoroz is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%82%73%73%70%69%63%51%64%83%89%88%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Portoroz

As spring transitions into summer, May in Portoroz, Slovenia, sees a notable surge in the UV Index, rising to a striking 8, categorized as very high. This increase signifies that sun exposure requires vigilance, with a recommended burn time of just 15 minutes. Comparatively, earlier months demonstrate a gradual climb: January starts with a low UV Index of 2, followed by a moderate 3 in February, and then a jump to 6 by April. As the days lengthen and temperatures rise, residents and visitors alike should prepare for intensified sun exposure during May, staying mindful of their skin protection. For more detailed information on UV levels throughout the year, check out Portoroz UV Index.

Maximum UV Index Levels in Portoroz for May

The chart shows the monthly maximum UV Index (UVI) for Portoroz in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Portoroz typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689987532
Data source: Portoroz May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

May Sunshine in Portoroz

May in Portorož, Slovenia, shines brightly with 372 hours of sunshine, marking a delightful peak in the spring season. As the days grow longer, the transition from winter to summer is beautifully reflected in the increasing sunlight hours—from 182 hours in January to a vibrant 344 hours in April. This upward trend continues into June, where sunshine reaches a stellar 417 hours, setting the stage for the sun-soaked summer months ahead. May serves as a bridge, inviting visitors to bask in the warming rays and enjoy the blossoming landscape, making it a perfect time to embrace the natural beauty of this coastal gem.

Monthly Sunshine Duration in Portoroz: May Highlighted

The May sunshine duration represents the total number of hours Portoroz experiences direct sunlight during the month of May, excluding cloudy or obstructed periods. This chart compares the sunshine duration of May with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec182h223h315h344h372h417h430h397h326h293h229h207h
Data source: Portoroz May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Portoroz During May

In Portorož, Slovenia, the month of May offers a 43% chance of sunny weather, which reflects a slight dip from the more promising sunshine in March and a notable decrease compared to the preceding April. This trend hints at a transitional period as spring gives way to early summer. Interestingly, while May’s sunshine likelihood doesn't quite reach the heights of subsequent months like July or August, it still maintains a respectable chance, suggesting that outdoor activities can be enjoyed, albeit with the potential for some unpredictable spring showers. As the year progresses into June and beyond, the chances of sunny weather tend to rise steadily, making late spring an enticing time for visitors seeking a balance of pleasant warmth and occasional cloud cover.

Percentage of Sunny Days in May in Portoroz

The chart illustrates the percentage of sunny days in Portoroz throughout the year, with May highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Portoroz experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec32%42%65%46%43%56%51%62%59%50%35%36%
Data source: Portoroz May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Portoroz in May

As spring blooms into summer, Portorož, Slovenia, experiences a remarkable increase in daylight, with May basking in approximately 14 hours of sunlight. This progression begins in January with just 9 hours, gradually extending through the months as the days grow longer. February sees a slight increase to 10 hours, then 11 hours in March, and a leap to 13 hours by April. Following this trend, June and July maintain a peak of 15 hours, providing ample time for outdoor activities and exploration. As summer wanes into August, daylight gradually diminishes to 14 hours once again, before tapering off—12 hours in September, and further down to 10 hours by October. The cycle then closes with shorter days returning in November and December, ultimately reminding us of the seasonal rhythms that shape our experience in this beautiful coastal town.

Average Daylight Hours in Portoroz for May

The chart illustrates the variation in daylight duration in Portoroz throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 9m10h 23m11h 56m13h 32m14h 54m15h 35m15h 13m14h 1m12h 29m10h 53m9h 29m8h 45m
Data source: Portoroz daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Portoroz

In May, Portoroz experiences a refreshing uptick in wind speed, averaging 4.5 m/s (10 mph), making it one of the breeziest months of the spring season. This slight increase from April’s 4.1 m/s (9 mph) signals a shift towards warmer, sunnier days, where the gentle winds coax locals and visitors alike to embrace outdoor activities along the stunning Adriatic coast. Interestingly, as the year progresses, the winds tend to fluctuate, peaking again in late autumn with 5.2 m/s (12 mph) in November. The contrasting patterns from May onward illustrate a dynamic climate, beckoning those who relish the invigorating embrace of the sea breeze.

Average May Wind Speed in Portoroz

The chart displays monthly wind speed patterns in Portoroz, with values for each month shown alongside May's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how May's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.33.63.54.14.5 m/s3.13.43.93.45.05.23.3
Data source: Portoroz May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Portoroz Compares to Other Months

Weather in Portoroz varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Portoroz, focusing on differences in temperature, rainfall, humidity, and UV levels.

In comparison of May and January weather, May typically offers a milder climate with temperatures ranging from a minimum of 10°C (50°F) to a maximum of 24°C (76°F), averaging at 17°C (64°F). Precipitation is more frequent in May, occurring on approximately 13 days, with a total of 105 mm (4.2 in) and humidity levels around 70%. In contrast, January presents a much cooler environment, with temperatures dipping to a minimum of -3°C (27°F) and peaking at only 13°C (56°F), averaging 7°C (46°F). January experiences less precipitation, totaling 58 mm (2.3 in) over about 7 days, but humidity is higher at 88%. For more detailed information about January weather, please visit Portoroz weather in January.

When comparing the weather in May and February, there are notable differences in temperature and humidity. May experiences milder temperatures, ranging from a minimum of 10°C (50°F) to a maximum of 24°C (76°F), with an average of 17°C (64°F), while February is much colder, with temperatures dipping as low as -3°C (27°F) and only reaching a maximum of 13°C (56°F), averaging around 8°C (47°F). The precipitation levels are similar, with May receiving 105 mm (4.2 in) over 13 days and February slightly higher at 106 mm (4.2 in) over 11 days. Additionally, February's humidity is higher at 82%, compared to May's 70%. For more detailed weather information, you can check Portoroz weather in February.

In comparing the weather between March and May, it's evident that May offers significantly milder temperatures, with averages reaching 17°C (64°F) compared to March's 10°C (50°F). The maximum temperatures in May can soar up to 24°C (76°F), making it a much warmer month overall. However, May also experiences higher precipitation, averaging 105 mm (4.2 in) over 13 days, compared to March's 57 mm (2.3 in) over just 7 days. Interestingly, humidity levels remain relatively consistent, with May at 70% and March slightly higher at 73%. Overall, May feels much more pleasant and inviting, while March can still feel quite chilly, as detailed in this Portoroz weather in March.

In comparing the weather conditions of April and May, it is clear that May tends to be warmer and wetter. May sees a minimum temperature of 10°C (50°F) and an average of 17°C (64°F), while April registers lower temperatures, with a minimum of 5°C (42°F) and an average of 13°C (56°F). Additionally, May experiences more precipitation, with 105 mm (4.2 in) falling over 13 days, compared to April's 86 mm (3.4 in) on just 8 days. Interestingly, while the humidity in April is slightly higher at 73%, May's humidity is close at 70%. For a closer look at April’s weather specifics, you can visit Portoroz weather in April.

May and June present contrasting weather patterns as spring transitions into summer. In May, temperatures range from a cooler 10°C (50°F) to a warmer 24°C (76°F), with an average of 17°C (64°F). This month experiences higher precipitation at 105 mm (4.2 in) over 13 days, contributing to a humidity level of 70%. In contrast, June sees a notable rise in temperatures, with minimums at 16°C (61°F) and maximums reaching 30°C (86°F), averaging around 23°C (73°F). Precipitation decreases significantly to 68 mm (2.7 in) spread over just 5 days, coupled with a slightly lower humidity of 69%. For a more detailed look at June weather, see Portoroz weather in June.

May and July present distinctly different weather patterns. In May, temperatures range from a cool minimum of 10°C (50°F) to a pleasant maximum of 24°C (76°F), with an average of 17°C (64°F). However, the month is characterized by significant precipitation, totaling 105 mm (4.2 in) over about 13 rainy days, and a humidity level of 70%, which adds to the dampness. In contrast, July experiences much warmer conditions, with minimum temperatures starting at 20°C (68°F) and peaking at 29°C (85°F), averaging 25°C (77°F). The month sees markedly less precipitation, with only 49 mm (1.9 in) falling across just 6 days, and a lower humidity level of 63%, making it feel drier and more comfortable. For more detailed insights about July weather, check out Portoroz weather in July.

May and August present quite different weather patterns. In May, temperatures range from a minimum of 10°C (50°F) to a maximum of 24°C (76°F), with an average of 17°C (64°F). This month experiences considerable rainfall, with 105 mm (4.2 in) of precipitation over about 13 days, contributing to a relatively high humidity level of 70%. In contrast, August offers warmer temperatures, with a minimum of 17°C (63°F) and a maximum reaching 30°C (87°F), averaging 26°C (78°F). Precipitation significantly decreases to 58 mm (2.3 in) over just 6 days, and humidity lowers to 51%. For more insights into the weather in August, you can explore Portoroz weather in August.

May and September offer distinct weather experiences, with May typically being cooler and wetter, while September ushers in milder temperatures and slightly less humidity. In May, temperatures range from a low of 10°C (50°F) to a high of 24°C (76°F), accompanied by 105 mm (4.2 in) of precipitation over about 13 days. In contrast, September enjoys a warmer average temperature of 22°C (71°F), peaking at 28°C (82°F), but with a higher total rainfall of 171 mm (6.7 in) spread over 10 days. The humidity in May sits at 70%, while September is a bit drier at 64%. For more detailed insights, check out Portoroz weather in September.

In comparing the weather of May and October, both months feature similar average temperatures around 17°C (64°F), but they differ slightly in their daily temperature ranges. May sees a minimum of 10°C (50°F) and a maximum of 24°C (76°F), while October has temperatures ranging from a minimum of 11°C (52°F) to a maximum of 23°C (73°F). Precipitation levels are quite close, with May receiving 105 mm (4.2 in) over 13 days and October garnering 100 mm (4.0 in) across 10 days. However, October tends to have a higher humidity level at 83%, compared to May's 70%. For more specific insights into October weather, you can check Portoroz weather in October.

May and November present contrasting weather patterns. In May, temperatures range from a pleasant minimum of 10°C (50°F) to a maximum of 24°C (76°F), with an average temperature of 17°C (64°F). The month experiences moderate rainfall of 105 mm (4.2 in) spread over 13 days and a humidity level of 70%. In contrast, November sees cooler temperatures, with nightly lows of 6°C (42°F) and daytime highs reaching 19°C (67°F), resulting in an average of 13°C (56°F). The precipitation increases significantly to 183 mm (7.2 in), also over 13 days, and the humidity rises sharply to 89%. For more details about November weather, see Portoroz weather in November.

May and December present contrasting weather patterns. In May, temperatures are warmer, with minimums around 10°C (50°F) and maximums reaching 24°C (76°F), along with a moderate average of 17°C (64°F). The month also sees 105 mm (4.2 in) of precipitation over about 13 days, accompanied by a humidity level of 70%. Conversely, December experiences cooler temperatures, with a minimum of 4°C (39°F) and a maximum of 16°C (60°F), resulting in a lower average of 10°C (50°F). This month also has higher precipitation at 150 mm (5.9 in) over the same 13 days, but with increased humidity at 88%. For more detailed information, check out Portoroz weather in December.

Compare Portoroz's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Portoroz

As May unfolds in Portorož, it heralds a transition into warmer days, where the charming coastal atmosphere begins to thrive. With maximum temperatures reaching a pleasant 24°C (76°F) and an average of 17°C (64°F), visitors can enjoy longer daylight hours in a typically mild climate. However, don't forget your umbrella as this month also brings about a fair share of rain, with around 13 days of precipitation adding up to 105 mm (4.2 in). The humidity level hovers at a comfortable 70%, making it an ideal time to explore the stunning surroundings. For more insights on the weather patterns throughout the year, check out Portoroz Climate.