September 21 is generally a great time to visit Oslo. While there is a slight chance of rain (22%), showers are usually brief. Expect comfortable 15°C weather. You'll find plenty of company in Oslo this month as tourism activity remains quite robust.
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Essential Travel Info for Oslo
Currency
NOK
kr Norwegian krone
Language
Norwegian Nynorsk
+2 more
Driving
Right side
Connect
Most of Oslo is covered by 5G. Most of t...
Safety
Very High Safety
GPI: 1.465
Oslo Weather Forecast for September 21
"Mild & Comfortable. Expect average highs of 14.9°C. 22% chance of rain."
What to Wear in Oslo in September
Based on historical data for September 21, Oslo typically experiences temperatures between 8.9°C and 14.9°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (22% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Oslo
Smart Suitcase
- Light Jacket
- Long Pants
Average High
14.9°C
Daytime Peak
Average Low
8.9°C
Nighttime Low
Feels Like
14.9°C
🌤️ Feels accurate
Rain Chance
22%
Avg 1.4mm if it rains
Cloud Cover
70%
Overcast
Pressure
1013.9 hPa
High volatility
Oslo Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 93% 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
🔴 53 min to burn
Type III-IV
🟡 80 min to burn
Type V-VI
🟢 133 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
11.9°C
Pleasant
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Marine Conditions
Marine Life
No special warnings. Enjoy the swim!
Swim Index
❄️ Cold Water Hazard
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Norway
Flight Traffic
Busy
63/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~230
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Oslo
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:59
☀️ Noon
12:11
🌇 Sunset
18:23
⏱️ Daylight
12h 24m
Wind Speed
13 km/h
Gentle breeze
Sunshine
6.7 hrs
Direct Sun (Cloud-free)
Humidity
82%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Oslo
Smart Flight Estimator
Airport-to-Airport Logistics
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Add your home location in settings to see airport details.
Travel Health & Safety in Oslo
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Rapid pressure changes detected. High risk for meteosensitive people.
Weather unlikely to affect joint pain.
Fish are active due to pressure changes.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Zero seismic activity detected in 30 years.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Oslo on September 21 averages 14.9°C with a 22% precipitation probability. Wedding/Outdoor Event Score: 94/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Oslo Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Compare Other Cities
Same date (September 21) in other destinations
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📍 Is Oslo Worth Visiting on September 21?
Planning a trip to Oslo on September 21? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year offers a bracing seasonal atmosphere averaging 14.9°C with a 22% historical precipitation risk.
✈️ Travel Logistics: Approximately 230 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 7 vaccinations are recommended for Norway, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 15.8°C (polar plunge). Wave conditions are generally lake-like with heights around 0.22m.
📊 Historical Extremes: The hottest September 21 recorded in the last 30 years saw temperatures hit 20.5°C in 2019, while the coldest dropped to 4.6°C in 2022.