September Weather in Primorsko, Bulgaria

Last updated: August 21, 2025

Experience the delightful September weather in Primorsko, Bulgaria, where the maximum temperature reaches a sizzling 29°C (85°F) and the average temperature lingers around a comfortable 21°C (71°F). With minimum temperatures dipping to a brisk 13°C (56°F), this month offers a diverse climate ideal for both leisure and exploration. While you may encounter occasional showers—with precipitation amounting to 40 mm (1.6 in) over 7 days—the overall humidity of 63% ensures a refreshing atmosphere. Embrace the charm of early autumn as Primorsko transitions, making it a perfect destination for those seeking sun-soaked days and mild evenings.

September Temperature in Primorsko

In September, Primorsko, Bulgaria, experiences a delightful transition from summer to autumn. With minimum temperatures around 13°C (56°F) and an average of 21°C (71°F), the weather remains pleasantly warm, perfect for enjoying the beautiful coastal landscapes. As daytime highs reach up to 29°C (85°F), the climate still retains a balmy summer feel, inviting beachgoers for one last swim before the cooler months set in. This gradual cooling trend paves the way for October’s lower temperatures, making September an ideal month for both outdoor adventures and relaxing by the sea.

September Weather in Primorsko: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Primorsko, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Primorsko, September 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).
JanFebMarAprMayJunJulAugSepOctNovDec414345516170747670625447
Data source: Temperature data for Primorsko generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Primorsko

In September, Primorsko experiences a notable increase in precipitation, receiving about 40 mm (1.6 in) of rain over approximately 7 days. This marks a shift from the dry days of August, which recorded only 20 mm (0.8 in) across merely 3 days. As summer transitions to autumn, the uptick in rainfall sets the stage for October and November, which are the wettest months of the year, with 106 mm (4.2 in) and 110 mm (4.3 in), respectively. This pattern suggests that September serves as a pivotal bridge to the wetter season, indicating a gradual shift in weather conditions as the region prepares for the cooler, rainier months ahead.

September Precipitation Trends in Primorsko

The chart displays monthly precipitation patterns in Primorsko, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Primorsko, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec98686157375936204010711094
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Primorsko

As summer transitions to autumn, September in Primorsko, Bulgaria, showcases a slight rebound in humidity levels, averaging 63%. This marks an increase from the drier months of July and August, where humidity levels dipped to 69% and 60% respectively. While September remains more comfortable than the peak winter months, which hover around 84% humidity, the shift hints at the coming cooler and wetter season. Overall, the trend reflects a gradual increase in moisture as the year progresses, with a notable rise expected in October, reaching 76%. This blend of crisp air and lingering warmth makes September a uniquely appealing time in Primorsko.

September Average Humidity in Primorsko

This chart illustrates the average monthly humidity levels in Primorsko, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Primorsko is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%81%79%75%77%71%69%60%63%76%81%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Primorsko

As summer transitions into fall, September in Primorsko, Bulgaria, showcases a notable drop in the UV Index, settling at 7 which falls in the high exposure category. This marked decrease from the scorching 9 found from May through August means sun-seekers can still bask in the sun for up to 25 minutes without significant risk of sunburn. While September still calls for sun protection, it signals a more moderate, yet enjoyable, climate ideal for outdoor activities. With this gradual shift, the UV Index serves as a gentle reminder of the changing seasons. For more detailed information, visit Primorsko UV Index.

Maximum UV Index Levels in Primorsko for September

The chart shows the monthly maximum UV Index (UVI) for Primorsko in September, 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 September, the maximum UV index in Primorsko typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec246799997532
Data source: Primorsko September 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.

September Sunshine in Primorsko

As summer transitions into autumn, September in Primorsko, Bulgaria still basks in a generous 342 hours of sunshine, making it a delightful time to enjoy the lingering warmth. Although this marks a decline from the sun-soaked peak of July, with its impressive 429 hours, September maintains a bright charm that invites locals and visitors alike to explore the coastal beauty. With sunlight gradually tapering off as the year progresses—dropping to 285 hours in October—this month offers a perfect balance of warmth and mildness, ideal for leisurely beach days and outdoor adventures before the chill of winter sets in. The trend of decreasing daylight hours reminds us to seize the last sunny days of the season, ensuring that September remains a vital part of Primorsko’s vibrant year.

Monthly Sunshine Duration in Primorsko: September Highlighted

The September sunshine duration represents the total number of hours Primorsko experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec162h228h293h348h397h409h429h404h342h285h224h213h
Data source: Primorsko September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Primorsko During September

As summer transitions into autumn, the likelihood of sunny weather in September in Primorsko, Bulgaria, remains relatively favorable, with a 49% chance of sunshine. While this figure marks a slight dip from the peak summer months of July and August, which boast over 75% sunshine, it still holds promise for those looking to enjoy milder temperatures and pleasant days. The pattern reveals that September retains a greater chance of sunshine compared to the colder months that follow, making it a wonderful time for outdoor activities and soaking up the last rays of summer before the clouds settle in for autumn.

Percentage of Sunny Days in September in Primorsko

The chart illustrates the percentage of sunny days in Primorsko throughout the year, with September 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 Primorsko experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec27%43%45%44%49%51%80%77%49%25%28%30%
Data source: Primorsko September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Primorsko in September

As summer fades and September arrives in Primorsko, Bulgaria, the daylight begins its gradual decline, offering around 12 hours of sunshine each day. This month acts as a gentle transition, as daylight hours decrease from the peak of 15 hours seen in June, while still basking in the lingering warmth of late summer. Following September, the days grow shorter, dipping to 11 hours of daylight in October and ultimately returning to the 9 hours typical of winter months. This progressive shift not only reflects the changing seasons but also invites residents and visitors alike to savor the last golden rays of the sun before autumn fully sets in.

Average Daylight Hours in Primorsko for September

The chart illustrates the variation in daylight duration in Primorsko throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 28m10h 33m11h 57m13h 22m14h 35m15h 12m14h 52m13h 48m12h 26m11h 1m9h 46m9h 7m
Data source: Primorsko daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Primorsko

As summer gracefully transitions to autumn, September in Primorsko, Bulgaria brings a refreshing change with an average wind speed of 4.8 m/s (11 mph). This moderate breeze feels invigorating after the warmer months, creating a perfect atmosphere for outdoor activities. Notably, September's winds are slightly stronger than both July and August, hinting at the seasonal shift. Following this transition, October typically sees an increase to 5.9 m/s (13 mph), further underscoring the arrival of fall. This trend of increasing winds highlights the dynamic climate in Primorsko, promising a vibrant experience for both locals and visitors as the summer tranquility gradually gives way to the briskness of autumn.

Average September Wind Speed in Primorsko

The chart displays monthly wind speed patterns in Primorsko, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec5.64.94.93.53.73.13.83.74.8 m/s5.94.56.0
Data source: Primorsko September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Primorsko Compares to Other Months

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

September and January present contrasting weather patterns. In September, temperatures range from a mild 13°C (56°F) at night to a warm average of 21°C (71°F) during the day, peaking at 29°C (85°F). This month experiences relatively low precipitation, totaling 40 mm (1.6 in) over about 7 days, accompanied by a moderate humidity of 63%. In stark contrast, January is characterized by chilly temperatures, with nighttime lows plummeting to -7°C (19°F) and an average daytime temperature of just 5°C (42°F), reaching a maximum of 16°C (61°F). This winter month sees significantly higher rainfall, accumulating 98 mm (3.9 in) over 11 days, alongside a higher humidity level of 84%. For a closer look at January weather specifically in Primorsko, check Primorsko weather in January.

September weather offers a pleasant transition into autumn, with average temperatures ranging from a mild 21°C (71°F) to a warm 29°C (85°F). Characterized by relatively low humidity at 63% and just 40 mm (1.6 in) of precipitation over approximately seven days, September is typically favorable for outdoor activities. In contrast, February presents a stark chill, with average temperatures dipping to just 6°C (44°F) and reaching a maximum of 16°C (61°F). This month experiences higher humidity at 81%, and more precipitation at 68 mm (2.7 in) over nine days, making it feel much colder. For a closer look at February weather specifics, you can visit Primorsko weather in February.

When comparing the weather in September and March, notable differences emerge. September enjoys milder temperatures, with a minimum of 13°C (56°F) and an average of 21°C (71°F), peaking at a comfortable 29°C (85°F). This month also experiences moderate precipitation of 40 mm (1.6 in) over approximately 7 days, accompanied by a humidity level of 63%. In contrast, March is chillier, with temperatures dipping to a minimum of -6°C (21°F) and averaging 7°C (46°F), only rising to a maximum of 19°C (66°F). March is wetter, recording 61 mm (2.4 in) of precipitation over about 10 days, and features higher humidity at 79%. For more detailed weather insights, you can explore Primorsko weather in March.

When comparing the weather in September to that of April, there's a notable difference in temperatures and humidity levels. September typically enjoys a warmer climate with average temperatures peaking at 21°C (71°F) and maximum highs reaching up to 29°C (85°F), while April experiences much cooler conditions, with an average of just 10°C (51°F) and highs of 22°C (72°F). Additionally, September has lower humidity at 63%, compared to April's higher humidity level of 75%. Precipitation is relatively similar in both months, with April receiving slightly more rainfall at 57 mm (2.2 in) over 8 days compared to September's 40 mm (1.6 in) over 7 days. For more detailed information, you can check Primorsko weather in April.

September tends to be warmer than May, with average temperatures reaching 21°C (71°F) compared to May's 16°C (61°F). The maximum temperature in September can climb to 29°C (85°F), while in May, it peaks at 25°C (78°F). In terms of precipitation, both months are relatively similar, with September experiencing 40 mm over 7 days and May recording slightly less at 37 mm over 8 days. However, humidity levels are higher in May at 77%, compared to September's 63%. For more detailed information, you can check Primorsko weather in May.

When comparing the weather in September and June, we find that both months share similar temperature ranges, with minimums around 13°C (55-56°F), average temperatures of about 21°C (70-71°F), and maximums peaking at 29°C (84-85°F). However, June experiences slightly higher humidity at 71% compared to September's 63%. Additionally, June sees more precipitation, averaging 59 mm over 9 days, whereas September has less rainfall at 40 mm across 7 days. For a detailed look at June weather in Primorsko, check out this link: Primorsko weather in June.

In comparing the weather patterns of September and July, it's clear that July tends to be warmer, with average temperatures around 24°C (75°F) compared to September's average of 21°C (71°F). The maximum temperatures in July reach up to 30°C (87°F), slightly surpassing September's peak of 29°C (85°F). Humidity levels are also higher in July at 69%, while September is a bit more comfortable at 63%. Interestingly, both months experience similar precipitation levels, with July recording 36 mm (1.4 in) over 6 days and September slightly higher at 40 mm (1.6 in) over 7 days. For more detailed insights into July's climate, you can visit Primorsko weather in July.

In comparing the weather between August and September, we see a notable shift in temperatures and precipitation patterns. August tends to be warmer, with an average temperature of 24°C (76°F) compared to September's average of 21°C (71°F). The maximum temperatures in August reach up to 31°C (88°F), whereas September's highs are capped at 29°C (85°F). Additionally, August is drier, experiencing only 20 mm (0.8 in) of precipitation over 3 days, while September sees increased rainfall totaling 40 mm (1.6 in) across 7 days. Humidity levels are relatively similar, lingering around 60% in August and 63% in September. For more details on August weather, you can visit Primorsko weather in August.

In comparing the weather between September and October, there's a noticeable shift in temperature and precipitation patterns. September enjoys a warmer average temperature of 21°C (71°F), with highs reaching 29°C (85°F), while October sees a drop in the average to 17°C (62°F), with maximum temperatures of 28°C (83°F). Additionally, October experiences significantly more rainfall, totaling 106 mm (4.2 in) over 10 days, compared to September's 40 mm (1.6 in) across 7 days. The humidity also rises in October, reaching 76%, up from September's 63%. For more details on the weather in October, you can check Primorsko weather in October.

September often presents a warm and pleasant climate, with average temperatures around 21°C (71°F) and highs reaching up to 29°C (85°F). However, as the month transitions to November, the weather becomes considerably cooler, with average temperatures dropping to 12°C (55°F) and nighttime lows plummeting to 2°C (36°F).

In terms of precipitation, September sees about 40 mm (1.6 in) over roughly 7 days, making it relatively drier than November, which experiences 110 mm (4.3 in) spread over 13 days. This increase in humidity from 63% in September to 81% in November further emphasizes the shift in weather patterns. For a detailed overview of November weather conditions, you can visit Primorsko weather in November.

When comparing the weather in September and December, it's clear that there’s a significant shift in temperature and precipitation. September boasts a mild climate with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 29°C (85°F), accompanied by relatively low precipitation of 40 mm (1.6 in) over 7 days and a humidity level of 63%. In contrast, December presents a much colder environment, with temperatures dipping as low as -2°C (28°F) and averaging around 8°C (48°F). Precipitation also increases to 94 mm (3.7 in) over 12 days, and the humidity rises to 84%. For more detailed insights, check Primorsko weather in December.

Compare Primorsko's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Primorsko

As summer gently transitions to autumn, September in Primorsko offers a delightful blend of warmth and mildness. With pleasantly warm temperatures and a notable decrease in precipitation compared to the sweltering peak of summer, this month invites longer outings and leisurely exploration without the crowds. While the sea remains inviting, the cooler evenings serve as a soothing reminder of the changing season. With humidity hovering at a comfortable level, September is an ideal time for outdoor activities and enjoying the stunning coastal scenery. For more insights into what to expect throughout the year, visit Primorsko Climate.