Last updated: August 21, 2025
Sofia, Bulgaria, in September presents a dynamic weather spectrum, with maximum temperatures reaching a warm 32°C (90°F), while the average settles around a mild 16°C (61°F). As the month progresses, temperatures can dip to a chilly -2°C (28°F) at night. Rainfall is relatively moderate, with an average precipitation of 25 mm (1.0 in) occurring across four days, contributing to the heightened humidity levels, which average 59%. This transitional period marks a shift towards autumn, offering a unique blend of summer warmth and the crispness of fall.
In September, Sofia, Bulgaria begins to experience a delightful transition as summer gives way to autumn. With temperatures ranging from a brisk -2°C (28°F) at night to a pleasant 32°C (90°F) during the day, visitors can enjoy a balanced climate that encourages outdoor exploration. The average temperature of 16°C (61°F) presents an ideal backdrop for picturesque strolls through the city's historic streets, where the fading summer heat meets the refreshing coolness of approaching fall. This month marks the last hurrah of warm weather, as nightly lows signal that cooler days are on the horizon. Thus, September in Sofia offers a unique blend of warmth and charm, perfect for those looking to soak in the rich culture of this vibrant city.
September marks a gentle transition for Sofia, Bulgaria, as it experiences a dip in precipitation, recording only 25 mm (1.0 in) over 4 days. This decline follows the summer months, where rainfall reached higher levels, particularly in June with 87 mm (3.4 in). In contrast, September's lighter showers signal the onset of autumn, providing a refreshing change after the sweltering heat of August, which saw merely 33 mm (1.3 in) over 7 days. As the month unfolds, the city's landscape begins to shift, with fewer rain-soaked days paving the way for crisp, clear skies and the vibrant hues of fall foliage. This trend of decreasing precipitation continues into the early autumn, indicating a gradual transition towards the wetter months ahead.
As summer transitions to autumn, September in Sofia, Bulgaria experiences a noticeable shift in humidity. After a seasonal low of 50% in August, the humidity rises to 59%, signaling the gradual approach of the wetter months ahead. This increase marks the beginning of a more humid period, as temperatures cool and the air retains more moisture. Notably, this rise in humidity is part of a broader trend where levels peak during the winter months, with January and December showcasing the highest figures at 89%. Overall, September serves as a gentle reminder of the changing seasons in Sofia, blending the remnants of summer with the anticipation of autumn's embrace.
As we transition into September in Sofia, Bulgaria, the UV Index begins to moderate after the intense summer months. With an Index rating of 7, categorized as high, it signals a need for caution during outdoor activities, as the burn time reduces to 25 minutes for unprotected skin. This pattern reflects a gradual cooling trend compared to the very high indices of June and July, where protection was crucial within just 15 minutes. While early autumn brings a reprieve, it’s still essential to stay aware of UV exposure. For more details and to keep track of the UV levels throughout the year, visit the Sofia UV Index.
UV Risk Categories
September in Sofia, Bulgaria, serves as a beautiful bridge between the vibrant summer months and the crisp arrival of autumn. With 342 hours of sunshine, the city basks in pleasant warmth, reminiscent of July and August yet a step away from their peak. This trend of abundant sunlight persists through the fall, even as October shows a gentle decline to 287 hours. The days begin to shorten, but September’s golden rays create an inviting atmosphere, perfect for exploring the city’s rich history and stunning landscapes. As the year transitions, the sun-soaked days of September invite both locals and travelers to savor the lingering warmth before winter’s arrival.
In Sofia, Bulgaria, the likelihood of sunny weather in September stands at a moderate 54%, reflecting a pleasant transition from the intense summer heat. Following the sun-drenched months of July and August, which boast impressive chances of 73% and 74% respectively, September offers a nice balance with its fair share of sunny days. This month marks the end of summer's peak, presenting a gradual decline in sunshine yet still providing a significant opportunity for outdoor activities. As the year progresses into October with a 44% chance of sun, September appears to be a sweet spot for those hoping to soak up the last rays of warm weather before autumn sets in.
As summer fades, September in Sofia, Bulgaria, brings a beautiful transition in daylight duration, offering approximately 12 hours of sunlight each day. This month marks a gentle decline from the peak of 15 hours in June, signaling the approach of autumn. The daylight gradually reduces as the year progresses, with October following closely at 11 hours. This pattern highlights the rhythmic ebb and flow of daylight throughout the year, where each season reveals its own charm, inviting residents and visitors alike to enjoy the changing landscape as it shifts from vibrant summer hues to the softer tones of fall.
As September arrives in Sofia, Bulgaria, the winds begin to shift, resembling a gentle transitional whisper from summer to fall. With an average wind speed of 2.0 m/s (5 mph), the briskness in the air serves as a refreshing reminder of the changing season. This slight increase from the quieter months of July and August, which feature calmer winds at 2.0 m/s (4 mph) and 1.8 m/s (4 mph) respectively, sets the tone for the month. Notably, September's winds return to a pace akin to earlier in the year, signaling a revival of movement as nature prepares for the cooler days ahead. The blend of moderate winds and the onset of autumn creates an invigorating atmosphere, making it a perfect time for outdoor exploration amidst Sofia's picturesque landscapes.
Weather in Sofia varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sofia, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January offer contrasting weather conditions. In September, temperatures range from a chilly minimum of -2°C (28°F) to a warm average of 16°C (61°F), reaching highs of up to 32°C (90°F). The month experiences less precipitation, with only 25 mm (1.0 in) falling over four days and humidity averaging 59%. In stark contrast, January's temperatures plummet, with minimums averaging -25°C (-14°F) and maximums peaking at just 12°C (54°F). This winter month sees significantly more precipitation, totaling 55 mm (2.2 in) over nine days, accompanied by higher humidity levels at 89%. For a detailed look at January weather, you can refer to Sofia weather in January.
September weather presents a mild and diverse climate, with temperatures ranging from a chilly -2°C (28°F) at night to a warm maximum of 32°C (90°F) during the day, while experiencing relatively low precipitation of 25 mm (1.0 in) over just 4 days and a humidity level of 59%. In contrast, February offers a much colder environment, with temperatures dipping to a minimum of -22°C (-8°F) and averaging only 2°C (36°F), peaking at a modest 18°C (64°F). This month sees more precipitation, totaling 47 mm (1.8 in) across 8 days, and a higher humidity at 85%. For a more detailed look at the weather specifics for February, check out Sofia weather in February.
September is characterized by milder temperatures, with average highs reaching up to 32°C (90°F) and a pleasant average of 16°C (61°F). In contrast, March experiences much colder weather, featuring average highs of only 22°C (71°F) and lows that can drop to -20°C (-3°F). While September sees relatively low precipitation at 25 mm (1.0 in) over just 4 days, March is much wetter, accumulating 74 mm (2.9 in) across 11 days. Additionally, March has higher humidity levels at 83%, compared to September's 59%. For more details on the weather specifics in March, you can visit Sofia weather in March.
When comparing the weather in September and April, notable differences emerge. September typically enjoys milder temperatures, with an average of 16°C (61°F) and maximums reaching up to 32°C (90°F), while April is cooler, averaging just 9°C (49°F) with maximums of 25°C (78°F). Additionally, September experiences lower humidity (59%) and less precipitation, averaging 25 mm (1.0 in) over about 4 days, whereas April sees higher humidity levels (71%) and almost double the precipitation at 50 mm (2.0 in) spread across roughly 10 days. For more detailed insights, you can explore Sofia weather in April.
September and May present contrasting weather patterns. In September, temperatures can range from a brisk -2°C (28°F) at night to a warm 32°C (90°F) during the day, with an average temperature of 16°C (61°F). The month sees relatively low precipitation at 25 mm (1.0 in) over just 4 days, accompanied by a humidity level of 59%. In contrast, May brings more moderate temperatures, with a minimum of 1°C (34°F), an average of 14°C (57°F), and a maximum of 29°C (84°F). However, it is wetter with 65 mm (2.6 in) of precipitation spread over 14 days and higher humidity at 73%. For more details, you can check Sofia weather in May.
When comparing the weather in September and June, several key differences emerge. September experiences a broader temperature range, with minimums dipping to -2°C (28°F) and maximums reaching up to 32°C (90°F), while June maintains a milder range, with temperatures ranging from 4°C (39°F) to 32°C (91°F). Additionally, June is significantly wetter, with 87 mm (3.4 in) of precipitation over 16 days, compared to September's modest 25 mm (1.0 in) of rain over just 4 days. Humidity levels also differ, with June having a higher average of 67% compared to September's 59%. For a more detailed look at June's weather, you can check out Sofia weather in June.
When comparing the weather in September and July, we see notable differences in both temperature and precipitation. September features a wider temperature range, with minimums dropping to -2°C (28°F) and maximums reaching 32°C (90°F), yielding an average of 16°C (61°F). In contrast, July is generally warmer, with temperatures ranging from a minimum of 8°C (47°F) to a maximum of 35°C (95°F) and an average of 20°C (68°F). Additionally, July experiences significantly more rainfall, with 67 mm (2.7 in) over 11 days compared to September's 25 mm (1.0 in) across just 4 days. The humidity is also higher in July at 68%, compared to 59% in September. For a deeper look at July's climate, check out Sofia weather in July.
September weather in Sofia exhibits a notable drop in temperature compared to August, with minimums reaching -2°C (28°F) and an average of 16°C (61°F), contrasting sharply with August's minimum of 7°C (44°F) and average of 20°C (69°F). While September can peak at 32°C (90°F), it generally feels milder, especially given the decreased humidity of 59% compared to August's 50%. Additionally, September experiences slightly less precipitation at 25 mm (1.0 in) over 4 days, while August sees 33 mm (1.3 in) spread over 7 days. For more detailed insights on August weather, visit Sofia weather in August.
In comparing the weather between September and October, it is evident that October tends to be cooler and slightly wetter. September boasts an average temperature of 16°C (61°F), with maximum highs reaching up to 32°C (90°F), while October's average temperature drops to 10°C (51°F), with a maximum of 28°C (84°F). Additionally, October experiences increased precipitation, totaling 44 mm (1.7 in) over 6 days compared to September's 25 mm (1.0 in) over just 4 days. Humidity levels also rise significantly in October, peaking at 79% compared to September's 59%. For more detailed information, check out Sofia weather in October.
September and November present distinctly different weather patterns. In September, temperatures range from a minimum of -2°C (28°F) to a maximum of 32°C (90°F), with an average of 16°C (61°F). The month sees relatively low precipitation of 25 mm (1.0 in) over just 4 days, accompanied by a moderate humidity level of 59%. In contrast, November experiences colder conditions with a minimum temperature of -14°C (6°F) and a maximum of 22°C (73°F), averaging only 6°C (42°F). Precipitation increases to 37 mm (1.5 in) spread over 6 days, alongside a higher humidity level of 87%. For more detailed insights, you can check Sofia weather in November.
September offers a milder climate with temperatures ranging from a minimum of -2°C (28°F) to a maximum of 32°C (90°F), featuring an average temperature of 16°C (61°F) and relatively low precipitation at 25 mm (1.0 in) over just four days. In contrast, December brings significantly colder weather, with temperatures dropping to a minimum of -14°C (7°F) and peaking at 13°C (55°F), resulting in a chilly average of 1°C (34°F). The month also experiences more precipitation, totaling 68 mm (2.7 in) across 12 days, coupled with increased humidity at 89%. For more detailed weather information, check out Sofia weather in December.
As September ushers in the transition from summer to autumn, Sofia experiences a delightful shift in weather, characterized by cooler temperatures and a moderate amount of rainfall. While the maximum daytime warmth provides a lingering touch of summer, crisp mornings and evenings hint at the coming season. This month typically boasts lower humidity levels compared to the hot summer months, making for more comfortable outdoor exploration. With an average of only four rainy days and a total precipitation of around 25 mm, September's weather is relatively dry, allowing for pleasant strolls through the city's vibrant parks. To learn more about Sofia's weather patterns throughout the year, check out Sofia Climate.