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Weather in Slovenia in September – is it worth traveling to?

Is the weather good for travel in September? Find out what the weather is like in Slovenia to plan your trip accordingly.
Check flight prices to Slovenia on Avionero:
September

Is the weather good in Slovenia in September 2025?

OK Weather
Mild
🌧️
Rainy

For the past few decades, the average daily temperatures in Slovenia during September have been around +72°F.

In Slovenia the temperature rarely varies more than seven degrees between the different parts with the highest temperature +72°F in Ljubljana to +72°F in Ljubljana. So you should be able to pack for similar conditions wherever you go in the country.

Temperature, wind and humidity in September

Average
Ljubljana
☀️
+72°F
Avg. max. temperature
+36°F
Min.
+90°F
Max.
125 mm
Total precipitation
80%
Avg. humidity
0 m/s
Avg. wind
6 ☀️
Sunny Days
10 ⛅️
Cloudy
11 🌦
Rainy
Our opinion: Slovenia has OK weather in September.
Slovenia in September – what city is the…
  • rainiest? Ljubljana, with an average of 4 mm of rain and humidity of 80%;
  • warmest? Ljubljana, with daytime temperatures averaging +72°F;
  • windiest? Ljubljana, with an average of 0 m/s;
  • coolest? Ljubljana, with daytime temperatures averaging +72°F;

How good is the weather in Slovenia in September?

During September, the Slovenia is characterized by variable weather with air pressure around 1016 HPa and therefore elements of sun, rain, and wind – with a little extra emphasis on the latter two. The humidity in September ranges between 80% in Ljubljana and 80% in Ljubljana.

How warm is it in Slovenia during September?

Variable weather with sun, rain and wind: +72°F in average daily temperature.

This is how hot it usually is in September

The average daily temperatures above don't tell you everything about how hot it can be in Slovenia. For example, cold nights can make a big difference for those staying in tents or unheated houses. Extra hot days, on the other hand, can make a big difference for those who plan to engage in demanding physical training or competition. So here are some more temperatures for September:
Average
Ljubljana
  • Average maximum temperature for the month: +72°F;
  • Average minimum temperature for the month: +54°F;
  • Highest monthly temperature: +73°F;
  • Lowest monthly temperature: +50°F;

Monthly temperatures:

Average
Ljubljana
  • Warmest: July with an average +81°F during the day;
  • Coldest: January with an average +39°F of the day;
  • Hottest month in hottest city: July in Ljubljana;
  • Coldest month in coolest city: January in Ljubljana;

Winds in Slovenia during September

Wind speed in Slovenia in September based on historical data:
Average
Ljubljana

September tends to offer light winds averaging 0 m/s. However, coastal cities may experience breezes during the mornings and afternoons.

Comparison between cities in September:

  • Highest average wind speed: Ljubljana with 1 m/s;
  • Lowest average wind speed: Ljubljana with 1 m/s;
  • Windiest day of the month: Ljubljana with 1 m/s;
  • The least windy day of the month: Ljubljana with 0 m/s;

Humidity and precipitation in Slovenia in September

Amount of rainfall in mm during September in Slovenia based on historical data:
Average
Ljubljana
September tends to be an extremely humid month with 78% humidity and 93 mm rainfall. In general the humidity tends to be a little lower in mountainous regions and more humid closer to water.

Comparison between cities in September:

Average
Ljubljana
  • Highest average rainfall: Ljubljana with 125 mm;
  • Lowest average rainfall: Ljubljana with 125 mm;
  • Most number of rainy days: Ljubljana with 11 rainy days;
  • Least number of rainy days: Ljubljana with 11 rainy days;
  • Highest risk of rain during the day: Ljubljana with 37%;
  • Least risk of rain during the day: Ljubljana with 37%;
  • Highest average humidity: Ljubljana with 80%;
  • Lowest average humidity: Ljubljana with 80%;

Tips for traveling to Slovenia in September

Looking for some tips for traveling to the sun, snow, or whatever you're aiming for Slovenia? Activities, weather, and clothing are closely linked. In addition, it's important to pack only what you really need so you don't have to worry about heavy packing or paying extra baggage fees.

Here is some advice on what to pack and what kind of activities you can do in the Slovenia based on the weather that September is expected to bring. The advice applies to the country as a whole – local weather and possible activities may differ somewhat.

rainy, mild weather with light winds and very high humidity in September
Avionero

Pack right for September

The weather makes a difference when it comes to packing - especially which items should go in your suitcase. The tips below are designed to help you pack light and right without carrying more than necessary.
  • For light showers, an umbrella or a thin and light rain cape is usually sufficient, while more rain may require rainwear and rain boots.
  • Cool weather is between warm and cold. This means you can bring long pants and/or a longer skirt and an extra sweater. Be aware that cool days can alternate with cold nights - it may be wise to also pack a hat, gloves and a scarf.
  • Light winds are probably most comfortable in hot weather but is cooling in cool and cold weather. If it is hot (when the air temperature is about 30 degrees), the wind can have a warming effect. A thin, windproof jacket and long trousers help to counteract these effects.
  • High humidity means that the air conducts heat to and from the skin more easily. For example, if the air is hot (above skin temperature), it will be harder to stay cool. On the other hand, if the air is cool or cold, it is more difficult to stay warm. In high humidity, the choice of clothing makes less of a difference. However, your physical activity plays a bigger role.

FAQ

Frequently asked questions about the weather in Slovenia in September:

What can you do outside when it's warm in Slovenia?

Bathing and sunbathing can be suitable. Warm (but not hot) days are also good for activities that are not so physically demanding: sightseeing on foot, by boat, on a scooter, camel riding. You can also exercise easily as long as you make sure to cool down and quench thirst.

Is September a good time to visit Slovenia?

It’s always a good time to visit Slovenia, but the weather is changeable in September, so plan a mix of indoor and outdoor activities and exploring, and pack for every eventuality.

Monthly weather in Slovenia

Source of the data

For this page, we’ve looked at the typical weather in Slovenia, based on historical hourly weather data from January 1, 1979, to December 31, 2023.

For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.