Last updated: August 27, 2025
In September, Postojna, Slovenia experiences a dynamic mix of weather conditions, making it a captivating month for visitors. With temperatures ranging from a crisp 2°C (36°F) at night to a pleasant maximum of 28°C (83°F) during the day, the weather offers a refreshing transition into autumn. The average temperature hovers around 15°C (60°F), ideal for exploring the beautiful landscapes. However, travelers should prepare for occasional rain, as 205 mm (8.1 in) of precipitation falls over 13 days, coupled with a humidity level of 64%. This month promises both sunny days and intermittent showers, providing a unique backdrop for enjoying the wonders of Postojna.
As summer gracefully transitions to autumn, Postojna, Slovenia in September showcases a delightful shift in temperatures. The month begins with a minimum of around 2°C (36°F), climbing to a comfortable average of 15°C (60°F), and peaks at a warm maximum of 28°C (83°F). This blend of mild warmth and crisp air creates an inviting atmosphere for outdoor exploration, as visitors can enjoy the beauty of the surrounding landscape. Compared to the sun-drenched heights of August, September offers a refreshing contrast, signaling the approach of cooler days while still retaining vestiges of summer's warmth. This makes it an ideal time for experiencing Postojna’s charming caverns and lush greenery amidst pleasantly mild weather.
In September, Postojna experiences a notable peak in precipitation, receiving 205 mm (8.1 in) of rain over 13 days. This significant amount not only highlights the transition into autumn but also marks the second-highest monthly total of the year, just behind the lush and vibrant May, which sees 206 mm (8.1 in). As summer fades, the weather shifts, bringing more frequent rainfall, indicative of the region’s temperate climate. The increased precipitation in September contributes to the lush greenery characteristic of Postojna, creating a striking landscape. This month’s rain sets the tone for the approaching cooler months, where precipitation remains substantial but tends to slightly decrease in October with 127 mm (5.0 in).
In September, Postojna, Slovenia experiences a noticeable rise in humidity, reaching 64% after the drier summer months. This marks a slight uptick from August's relatively low 51%, as the region transitions into autumn. The humidity levels in September indicate the beginning of the wetter season, setting the stage for the more humid months ahead, with October soaring to 83%. Throughout the year, the trend reveals a gradual decline from the winter peaks, where humidity hovers around the 88-89% range in January and November, down to the summer lows in July and August. As September arrives, it serves as a gentle reminder of the impending shift back to the prevalent moisture of autumn.
As summer fades into autumn, September in Postojna, Slovenia sees a UV Index of 7, placing it in the high exposure category. With a burn time of 25 minutes, this month marks a transition from the very high UV levels experienced in the peak summer months of June and July, where the index soared to 9. Although still requiring caution, September offers a bit of respite as the days grow shorter and temperatures begin to cool. It's a time when outdoor enthusiasts can still enjoy the sun, but it's wise to stay mindful of UV exposure, particularly during midday hours. For detailed information on UV Index trends in Postojna, visit Postojna UV Index.
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As summer gently fades into autumn, September in Postojna, Slovenia, offers a refreshing blend of warm days and cool nights, with an impressive 322 hours of sunshine. This marks a subtle decline from the peak of summer, reflecting a gradual transition from the sun-drenched months of July and June, which boast over 400 hours each. The lingering warmth of early fall allows residents and visitors alike to bask in the beautiful landscapes and crystal-clear skies before the chill of winter sets in. With each passing autumn month, the sunlight gradually wanes, yet September enchants with a tantalizing balance of light, reminding us of summer’s vibrant spirit while hinting at the serene beauty that awaits in the cooler months.
As summer transitions into autumn, September in Postojna, Slovenia showcases a delightful 54% chance of sunny weather, marking it as one of the more optimistic months for sunshine. This figure reveals a noteworthy surge in clarity compared to the earlier months of the year, particularly when juxtaposed against the colder months like January with only 22% and April at 36%. September's relatively high likelihood of sun becomes particularly inviting after a summer characterized by fluctuating sunshine; July and August hover around the mid-40s. Consequently, this month presents an ideal opportunity for outdoor activities or exploration, offering a perfect blend of pleasant weather and stunning autumnal scenery.
As summer gently fades into autumn, September in Postojna, Slovenia, offers a delightful 12 hours of daylight, reflecting a gradual transition from the sun-drenched days of July and August, which boast 15 and 14 hours respectively. This month marks a notable dip in sunlight, yet it still enjoys more daylight than both the approaching October, with its 10 hours, and the upcoming winter months. The progression from the longer days of May and June confirms a clear seasonal trend, where daylight gradually diminishes, inviting cooler evenings and the distinct charm of autumn. As the landscape begins to transform, September stands as a beautiful bridge, balancing between the brightness of summer and the cozy embrace of fall.
As September rolls into Postojna, Slovenia, the gentle whispers of the wind begin to mellow, with an average speed of 2.0 m/s (5 mph). This marks a slight decrease from the summer months, where breezes hovered around 2.1 m/s, indicating a transition toward autumn's embrace. Observing the broader yearly trend, the winds in September are among the calmest of the year, as they dip just below the earlier months, such as April and May, both at 2.5 m/s. The anticipation of cooler days ahead seems to echo through the air, suggesting a serene shift in the landscape as nature prepares for its seasonal change. Overall, September’s soft winds invite a reflective pause, bridging the vibrant energy of summer with the tranquil onset of fall.
Weather in Postojna varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Postojna, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January weather present a striking contrast in temperature and precipitation. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 28°C (83°F), with an average of 15°C (60°F), making it a much warmer month. However, it also sees significant rainfall, totaling 205 mm (8.1 in) over approximately 13 days, coupled with a humidity level of 64%. In contrast, January is characterized by much colder temperatures, with a minimum of -14°C (7°F) and a maximum of 11°C (52°F), averaging around 0°C (33°F). Precipitation in January is lighter, at 72 mm (2.8 in) over just 8 days, but the humidity is notably higher at 88%. For more detailed insights into January weather, visit Postojna weather in January.
September and February present strikingly different weather patterns. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 28°C (83°F), with an average of 15°C (60°F), making it a much warmer month overall. However, it also experiences considerable rainfall, with 205 mm (8.1 in) of precipitation over 13 days and a humidity level of 64%. In contrast, February features colder weather, with temperatures ranging from -12°C (10°F) to 19°C (67°F) and an average of just 3°C (38°F). The month sees less rainfall, totaling 128 mm (5.0 in) across 10 days, but a higher humidity level of 82%. For more insights about February weather specifically, you can check out Postojna weather in February.
September and March present contrasting weather patterns, significantly impacting daily life and activities. In September, temperatures range from a cool minimum of 2°C (36°F) to a warm maximum of 28°C (83°F), with an average of 15°C (60°F). This month also experiences substantial rainfall, totaling 205 mm (8.1 in) over 13 days, contributing to a humidity level of 64%. In contrast, March has a much colder climate, with temperatures dipping to a minimum of -17°C (2°F) and peaking at 21°C (70°F), averaging only 5°C (42°F). Precipitation in March is lower, measuring 97 mm (3.8 in) across 11 days, while humidity rises slightly to 73%. For a more detailed look at the weather in March, you can visit Postojna weather in March.
September and April present quite a contrast in weather conditions. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 28°C (83°F), with an average of 15°C (60°F). This month experiences significant rainfall, totaling 205 mm (8.1 in) over about 13 days, and carries a moderate humidity level of 64%. In contrast, April is cooler with temperatures ranging from -10°C (14°F) to 25°C (78°F) and an average of 10°C (50°F). While April receives less precipitation at 115 mm (4.5 in) spread over 12 days, it has a slightly higher humidity level of 73%. For more detailed insights, you can refer to Postojna weather in April.
When comparing the weather between September and May, both months exhibit similar average precipitation levels, each receiving around 206 mm (8.1 in) of rain, but they differ in their distribution. September experiences slightly higher maximum temperatures, reaching up to 28°C (83°F), compared to May's maximum of 26°C (79°F). However, May tends to have a marginally cooler minimum temperature of 1°C (34°F) versus September's 2°C (36°F). In terms of humidity, May is notably more humid at 70%, compared to September's 64%. This increased humidity in May is indicative of the prolonged rainfall, with an average of 20 rainy days, whereas September has 13 days of precipitation. For more detailed information, you can check Postojna weather in May.
When comparing the weather in September to that of June, one can see notable differences. September experiences a wider temperature range, with minimums dipping to 2°C (36°F) and maximums reaching 28°C (83°F), while June has higher averages, with minimums at 6°C (44°F) and maxima soaring up to 35°C (95°F). The average temperature in June is also warmer at 19°C (67°F) compared to September's 15°C (60°F). In terms of precipitation, September sees more rainfall with 205 mm (8.1 in) over 13 days, whereas June records only 110 mm (4.3 in) across 12 days. Humidity levels are slightly higher in June at 69%, compared to September's 64%. For more detailed information on June weather, you can refer to Postojna weather in June.
In comparing the weather of September and July, we can see notable differences in temperature and precipitation. July typically enjoys warmer conditions, with average temperatures around 20°C (68°F) and maximums reaching 33°C (91°F). In contrast, September starts to cool down, with average temperatures of 15°C (60°F) and highs peaking at 28°C (83°F). While July experiences less rainfall at 130 mm (5.1 in) over 14 days, September is wetter, with 205 mm (8.1 in) over 13 days. Humidity levels remain fairly consistent, with July at 63% and September slightly higher at 64%. For more detailed insights on July weather, you can check out Postojna weather in July.
September weather contrasts notably with August, showcasing cooler temperatures and increased precipitation. While August boasts a warmer average of 20°C (69°F) with maximum highs reaching 34°C (93°F), September's temperatures dip, with a minimum of 2°C (36°F) and an average of 15°C (60°F). Additionally, September experiences significantly more rainfall, accumulating 205 mm (8.1 in) over 13 days, compared to August's 126 mm (5.0 in) during the same number of days. The humidity levels also rise in September, averaging 64% compared to August's more comfortable 51%. For a detailed look at August weather specifics, check out Postojna weather in August.
September and October present a noticeable transition in weather patterns. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 28°C (83°F), with an average of 15°C (60°F). The month experiences significant rainfall, totaling 205 mm (8.1 in) over 13 days and maintaining a humidity level of 64%. Conversely, October sees a drop in temperatures, with a minimum of 0°C (32°F) and a maximum of 23°C (73°F), averaging 11°C (52°F). Precipitation decreases to 127 mm (5.0 in) across 10 days, and humidity rises to 83%. For more detailed information on October weather in Postojna, you can visit Postojna weather in October.
In September, the weather is generally warmer, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 28°C (83°F), and an average of 15°C (60°F). This month also experiences significant rainfall, totaling 205 mm (8.1 in) over 13 days, along with a humidity level of 64%. In contrast, November tends to be much cooler, with temperatures ranging from a minimum of -9°C (16°F) to a maximum of 18°C (65°F) and an average of 6°C (43°F). Although November sees less precipitation than September—176 mm (6.9 in) over 12 days—the humidity is notably higher at 89%. For more details, check the Postojna weather in November.
Comparing the weather in September and December reveals a stark contrast in temperature and conditions. September starts with milder temperatures, ranging from a minimum of 2°C (36°F) to a maximum of 28°C (83°F), while averaging around 15°C (60°F). This month also sees significant rainfall, with 205 mm (8.1 in) over 13 days and a humidity level of 64%. In contrast, December experiences much colder weather, with temperatures ranging from a frigid minimum of -13°C (9°F) to a maximum of 13°C (56°F), averaging just 2°C (36°F). Precipitation decreases slightly to 161 mm (6.3 in) over 11 days, but humidity rises to a notable 88%. For more detailed information on the December climate, visit Postojna weather in December.
As September arrives in Postojna, the weather begins to shift from the warmth of summer to the cooler embrace of autumn. This month is characterized by a comfortable average temperature, making it a delightful time for outdoor activities before the chill sets in. While the days can still see highs around 28°C, nighttime temperatures can plummet to a brisk 2°C, reminding us that summer is drawing to a close. With an average humidity of 64% and notable precipitation, September marks a transitional period where lush greens give way to the vibrant hues of fall. If you're planning a visit, be sure to check out the full details about the area's climate at Postojna Climate.