September 18 is generally a great time to visit Ljubljana. While there is a slight chance of rain (33%), showers are usually brief. Expect comfortable 20°C weather. As it's peak season for Ljubljana, we recommend booking your stay well in advance to secure the best rates.
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Essential Travel Info for Ljubljana
Currency
EUR
€ Euro
Language
Slovene
Driving
Right side
Connect
As of 2025, Ljubljana has excellent 5G a...
Safety
Very High Safety
GPI: 1.316
Ljubljana Weather Forecast for September 18
"Mild & Comfortable. Expect average highs of 19.9°C. 33% chance of rain."
What to Wear in Ljubljana in September
Based on historical data for September 18, Ljubljana typically experiences temperatures between 11.2°C and 19.9°C. We recommend packing light jacket, long pants, umbrella to stay comfortable. With a 33% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Ljubljana
Smart Suitcase
- Light Jacket
- Long Pants
- Umbrella
Average High
19.9°C
Daytime Peak
Average Low
11.2°C
Nighttime Low
Feels Like
19.9°C
🌤️ Feels accurate
Rain Chance
33%
Avg 3.4mm if it rains
Cloud Cover
66%
Light drizzle
Pressure
1017 hPa
Medium volatility
Ljubljana Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 94% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
Type I-II
🔴 35 min to burn
Type III-IV
🟡 53 min to burn
Type V-VI
🟢 88 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
16.5°C
Noticeable
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Slovenia
Flight Traffic
High
81/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~26
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Ljubljana
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:44
☀️ Noon
11:57
🌇 Sunset
18:10
⏱️ Daylight
12h 25m
Wind Speed
11 km/h
Light breeze
Sunshine
8.0 hrs
Direct Sun (Cloud-free)
Humidity
81%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Ljubljana
Smart Flight Estimator
Airport-to-Airport Logistics
unlock smart flight estimates
Add your home location in settings to see airport details.
Travel Health & Safety in Ljubljana
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Unhealthy for sensitive groups. Consider wearing a mask outdoors.
Regional Safety Profile
Seismic Activity
Moderate seismic activity. Occasional tremors possible.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Ljubljana on September 18 averages 19.9°C with a 33% precipitation probability. Wedding/Outdoor Event Score: 92/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Ljubljana Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 11
22.3°C • 23% rain
Score
98
September 12
22°C • 26% rain
Score
97
September 13
21.9°C • 25% rain
Score
97
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 18) in other destinations
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📍 Is Ljubljana Worth Visiting on September 18?
Planning a trip to Ljubljana on September 18? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year is characterized by pleasant mild weather averaging 19.9°C with a 33% historical precipitation risk.
✈️ Travel Logistics: Approximately 26 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 7 vaccinations are recommended for Slovenia, including COVID-19.
📊 Historical Extremes: The hottest September 18 recorded in the last 30 years saw temperatures hit 25.5°C in 2018, while the coldest dropped to 4.4°C in 2022.