September 12 is generally a great time to visit London. While there is a slight chance of rain (24%), showers are usually brief. Expect comfortable 19°C weather. As it's peak season for London, we recommend booking your stay well in advance to secure the best rates.
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Essential Travel Info for London
Currency
GBP
£ British pound
Language
English
Driving
Left side
Connect
London is unfortunately not noted for fr...
Safety
High Safety
GPI: 1.667
London Weather Forecast for September 12
"Mild & Comfortable. Expect average highs of 19.4°C. 24% chance of rain."
What to Wear in London in September
Based on historical data for September 12, London typically experiences temperatures between 11.4°C and 19.4°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (24% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for London
Smart Suitcase
- Light Jacket
- Long Pants
Average High
19.4°C
Daytime Peak
Average Low
11.4°C
Nighttime Low
Feels Like
19.4°C
🌤️ Feels accurate
Rain Chance
24%
Avg 1mm if it rains
Cloud Cover
65%
Overcast
Pressure
1015.8 hPa
High volatility
London Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
✓ This date historically delivers consistent weather 77% 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
🔴 40 min to burn
Type III-IV
🟡 60 min to burn
Type V-VI
🟢 100 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
15.1°C
Pleasant
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in United Kingdom
Flight Traffic
High
94/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~2,479
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in London
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:31
☀️ Noon
11:58
🌇 Sunset
18:25
⏱️ Daylight
12h 53m
Wind Speed
19 km/h
Gentle breeze
Sunshine
8.4 hrs
Direct Sun (Cloud-free)
Humidity
76%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for London
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 London
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
Rare minor tremors. Buildings are earthquake-resistant.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, London on September 12 averages 19.4°C with a 24% precipitation probability. Wedding/Outdoor Event Score: 93/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
London Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 16
19.2°C • 14% rain
Score
100
September 17
19.2°C • 14% rain
Score
100
September 6
20.9°C • 20% rain
Score
97
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 12) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is London Worth Visiting on September 12?
Planning a trip to London on September 12? 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 19.4°C with a 24% historical precipitation risk.
✈️ Travel Logistics: Approximately 2,479 landing slots available daily during this period, indicating peak tourist activity.
💉 Health Advisory: 8 vaccinations are recommended for United Kingdom, including COVID-19.
📊 Historical Extremes: The hottest September 12 recorded in the last 30 years saw temperatures hit 24.8°C in 2022, while the coldest dropped to 6.5°C in 2024.