September 21 is statistically one of the best days of the year in Cape Town. With minimal rain risk (14%) and pleasant highs of 19°C, it's ideal for outdoor adventures. As it's peak season for Cape Town, we recommend booking your stay well in advance to secure the best rates.
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Essential Travel Info for Cape Town
Currency
ZAR
R South African rand
Language
Afrikaans
+10 more
Driving
Left side
Connect
Many carriers (especially in Europe) cha...
Safety
Moderate Safety
GPI: 2.283
Cape Town Weather Forecast for September 21
"Mild & Comfortable. Expect average highs of 19°C. 14% chance of rain."
What to Wear in Cape Town in September
Based on historical data for September 21, Cape Town typically experiences temperatures between 10.2°C and 19°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (14% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Cape Town
Smart Suitcase
- Light Jacket
- Long Pants
Average High
19°C
Daytime Peak
Average Low
10.2°C
Nighttime Low
Feels Like
19°C
🌤️ Feels accurate
Rain Chance
14%
Avg 0.5mm if it rains
Cloud Cover
48%
Overcast
Pressure
1019.9 hPa
Medium volatility
Cape Town Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 100% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
06:00 - 10:00
16:00 - 18:00
Type I-II
🔴 24 min to burn
Type III-IV
🟡 36 min to burn
Type V-VI
🟢 60 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
14.5°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 South Africa
Flight Traffic
High
81/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~109
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Cape Town
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:38
☀️ Noon
12:40
🌇 Sunset
18:42
⏱️ Daylight
12h 3m
Wind Speed
20.4 km/h
Moderate wind
Sunshine
10.0 hrs
Direct Sun (Cloud-free)
Humidity
75%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Cape Town
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 Cape Town
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
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.
Air quality is acceptable. Sensitive individuals should limit prolonged outdoor exertion.
Regional Safety Profile
Seismic Activity
Zero seismic activity detected in 30 years.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Cape Town on September 21 averages 19°C with a 14% precipitation probability. Wedding/Outdoor Event Score: 100/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Cape Town 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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🌍 Explore the same date in different destinations around the world
📍 Is Cape Town Worth Visiting on September 21?
Planning a trip to Cape Town on September 21? 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°C with a 14% historical precipitation risk.
✈️ Travel Logistics: Approximately 109 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 9 vaccinations are recommended for South Africa, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 14°C (polar plunge). Wave conditions are generally surfers only with heights around 2.66m.
📊 Historical Extremes: The hottest September 21 recorded in the last 30 years saw temperatures hit 23.1°C in 2024, while the coldest dropped to 5.6°C in 2018.