Postojna
September
Weather in Postojna for September 2025
Your guide to Postojna weather in September - trends and predictions
Moderate Thunderstorm Risk Warning - See hour by hour.
Until now, September 2025 in Postojna is slightly cooler than the historical average by -0.7 °C.
Expect cooler weather in the next days in Postojna with the forecast suggesting a temperature of 18.9 °C, lower than the historical average.
In general, the average temperature in Postojna at the beginning of September is 25 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 13.7 °C by the end of September.
The climate of Postojna in September is notably wet, with an average of 15 rainy days, and a total of 160.6 mm of precipitation.
Official Weather Alert ⚠️
Temperatures
Rain 🌧️
15
Dry days
15
Rainy days
0
Snow days
19°/10°
Temperatures
14 km/h
Avg max wind
79 %
Avg humidity
Postojna Weather September
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Temperatures trend during September in Postojna
See the weather trend as well as the moving average line
September weather in Postojna day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Partly cloudy | 26° /14° | 0 mm | 7 | |
| 2 Sept. | Partly cloudy | 26° /14° | 1.1 mm | 7 | |
| 3 Sept. |  Moderate rain at times | 25° /13° | 7 mm | 6 | |
| 4 Sept. |  Sunny | 27° /13° | 0.2 mm | 7 | |
| 5 Sept. | Partly cloudy | 27° /13° | 6.8 mm | 7 | |
| 6 Sept. |  Patchy light rain with thunder | 21° /13° | 3.9 mm | 5 | |
| 7 Sept. | Sunny | 23° /11° | 0 mm | 6 | |
| 8 Sept. |  Light rain shower | 24° /11° | 0.8 mm | 5 | |
| 9 Sept. | Light rain shower | 19° /12° | 9.3 mm | 5 | |
| 10 Sept. | Light rain shower | 19° /12° | 53.7 mm | 5 | |
| 11 Sept. | Patchy rain possible | 20° /11° | 5.7 mm | 5 | |
| 12 Sept. | Moderate or heavy rain shower | 17° /8° | 32.3 mm | 4 | |
| 13 Sept. |  Light drizzle | 17° /8° | 2.8 mm | 4 | |
| 14 Sept. | Light rain | 16° /9° | 6.9 mm | 4 | |
| 15 Sept. | Patchy rain possible | 14° /6° | 0.2 mm | 3 | |
| 16 Sept. |  Moderate rain | 19° /10° | 16.4 mm | 1 | |
| 17 Sept. | Patchy rain possible | 17° /9° | 1.2 mm | 1.3 | |
| 18 Sept. | Sunny | 22° /8° | 0 mm | 1.4 | |
| 19 Sept. | Sunny | 24° /11° | 0 mm | 1.5 | |
| 20 Sept. | Sunny | 25° /11° | 0 mm | 5 | |
| 21 Sept. | Sunny | 24° /13° | 0 mm | 5 | |
| 22 Sept. | Sunny | 24° /13° | 0 mm | 5 | |
| 23 Sept. | Patchy rain possible | 21° /12° | 0.4 mm | 4 | |
| 24 Sept. | Moderate rain | 18° /14° | 13 mm | 4 | |
| 25 Sept. | Moderate rain | 9° /7° | 16.4 mm | 2 | |
| 26 Sept. |  Cloudy | 14° /6° | 0 mm | 2 | |
| 27 Sept. | Sunny | 15° /6° | 0 mm | 3 | |
| 28 Sept. | Partly cloudy | 14° /5° | 0 mm | 3 | |
| 29 Sept. |  Fog | 14° /4° | 0 mm | 3 | |
| 30 Sept. | Partly cloudy | 12° /2° | 0 mm | 4 | |
| Next | |||||
Important Notice
Our weather forecast for Postojna in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Postojna forecast closer to your planned date for the most up-to-date weather information.
Change Month
Postojna in September - FAQ
What are the expected maximum and minimum temperatures in Postojna during September?
Enjoy moderate daytime temperatures of up to 19° and cooler nights around 10°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Postojna during September?
Significant rainfall exceeding 160.6 mm is expected in Postojna during September, occurring over more than 15 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Postojna during September?
The average wind speed in Postojna during September is 14 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Postojna
Explore the daily rainfall trends and prepare for Postojnas September weather 💧
UV exposure in Postojna during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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