Historical data suggests significant rain risk (87%) on September 23. If you seek sun, consider a different date. Bring rain gear! You'll find plenty of company in San Jose this month as tourism activity remains quite robust.
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Essential Travel Info for San Jose
Currency
CRC
₡ Costa Rican colón
Language
Spanish
Driving
Right side
Connect
Cable TV channels have many American Eng...
Safety
High Safety
GPI: 1.732
San Jose Weather Forecast for September 23
"Rainy & Overcast. Expect average highs of 24.3°C. 87% chance of rain."
What to Wear in San Jose in September
Based on historical data for September 23, San Jose typically experiences temperatures between 17.1°C and 24.3°C. We recommend packing t-shirt, light clothing, umbrella to stay comfortable. With a 87% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for San Jose
Smart Suitcase
- T-Shirt
- Light Clothing
- Umbrella
Average High
24.3°C
Daytime Peak
Average Low
17.1°C
Nighttime Low
Feels Like
25.3°C
☀️ Minor difference
Rain Chance
87%
Avg 13.5mm if it rains
Cloud Cover
90%
Moderate rain
Pressure
1013.4 hPa
Low volatility
San Jose Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 96% 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
🔴 33 min to burn
Type III-IV
🟡 50 min to burn
Type V-VI
🟢 83 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
22.7°C
Humid/Sticky
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Costa Rica
Flight Traffic
Busy
68/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~80
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in San Jose
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:26
☀️ Noon
11:30
🌇 Sunset
17:33
⏱️ Daylight
12h 6m
Wind Speed
7.6 km/h
Light breeze
Sunshine
7.8 hrs
Direct Sun (Cloud-free)
Humidity
91%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for San Jose
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 San Jose
Travel Comfort Index
Real-time tourism conditions
Weather Quality
🌧️ Variable
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Active seismic zone. Multiple earthquakes per year.
Travel Alert: This region has elevated natural risks. We recommend registering with your embassy and keeping emergency numbers handy.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, San Jose on September 23 averages 24.3°C with a 87% precipitation probability. Wedding/Outdoor Event Score: 47/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
San Jose Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 22
24.4°C • 84% rain
Score
50
September 18
24.5°C • 85% rain
Score
49
September 21
24.4°C • 85% rain
Score
49
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 23) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is San Jose Worth Visiting on September 23?
Planning a trip to San Jose on September 23? 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 24.3°C with a 87% historical precipitation risk.
✈️ Travel Logistics: Approximately 80 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 9 vaccinations are recommended for Costa Rica, including COVID-19.
📊 Historical Extremes: The hottest September 23 recorded in the last 30 years saw temperatures hit 28°C in 2023, while the coldest dropped to 15.1°C in 2022.