April 21 sees frequent showers in Porto. Historical data shows a 45% chance of rain, so pack accordingly. Temperatures average 18°C. Porto is seeing high visitor numbers, so iconic spots may be busier than usual.
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Essential Travel Info for Porto
Currency
EUR
€ Euro
Language
Portuguese
Driving
Right side
Connect
Porto has 4G from all Portuguese carrier...
Safety
Very High Safety
GPI: 1.301
Porto Weather Forecast for April 21
"Mild & Comfortable. Expect average highs of 18°C. 45% chance of rain."
What to Wear in Porto in April
Based on historical data for April 21, Porto typically experiences temperatures between 10.8°C and 18°C. We recommend packing light jacket, long pants, umbrella to stay comfortable. With a 45% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Porto
Smart Suitcase
- Light Jacket
- Long Pants
- Umbrella
Average High
18°C
Daytime Peak
Average Low
10.8°C
Nighttime Low
Feels Like
18°C
🌤️ Feels accurate
Rain Chance
45%
Avg 4.2mm if it rains
Cloud Cover
62%
Overcast
Pressure
1014.6 hPa
Medium volatility
Porto Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 84% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 19:00
Type I-II
🔴 21 min to burn
Type III-IV
🟡 32 min to burn
Type V-VI
🟢 53 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
14.3°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 Portugal
Flight Traffic
Busy
70/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~172
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Porto
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:47
☀️ Noon
12:34
🌇 Sunset
19:21
⏱️ Daylight
13h 33m
Wind Speed
19.8 km/h
Gentle breeze
Sunshine
10.3 hrs
Direct Sun (Cloud-free)
Humidity
79%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Porto
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 Porto
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🟡 Busy
Price Level
💰💰 Moderate
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
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, Porto on April 21 averages 18°C with a 45% precipitation probability. Wedding/Outdoor Event Score: 81/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Porto Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
April 27
18°C • 27% rain
Score
92
April 24
18.2°C • 28% rain
Score
91
April 25
18.3°C • 25% rain
Score
91
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (April 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Porto Worth Visiting on April 21?
Planning a trip to Porto on April 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 18°C with a 45% historical precipitation risk.
✈️ Travel Logistics: Approximately 172 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 6 vaccinations are recommended for Portugal, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 16.1°C (polar plunge). Wave conditions are generally surfers only with heights around 1.69m.
📊 Historical Extremes: The hottest April 21 recorded in the last 30 years saw temperatures hit 23.3°C in 2024, while the coldest dropped to 5.8°C in 2022.