December 18 is statistically one of the best days of the year in San Jose. With minimal rain risk (14%) and pleasant highs of 24°C, it's ideal for outdoor adventures. As it's peak season for San Jose, we recommend booking your stay well in advance to secure the best rates.
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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 December 18
"Mild & Comfortable. Expect average highs of 24.4°C. 14% chance of rain."
What to Wear in San Jose in December
Based on historical data for December 18, San Jose typically experiences temperatures between 16.6°C and 24.4°C. We recommend packing t-shirt, light clothing 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 San Jose
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
24.4°C
Daytime Peak
Average Low
16.6°C
Nighttime Low
Feels Like
25.2°C
☀️ Feels accurate
Rain Chance
14%
Avg 1.3mm if it rains
Cloud Cover
56%
Light drizzle
Pressure
1013.5 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 100% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
20.7°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
High
92/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~108
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in San Jose
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:47
☀️ Noon
11:34
🌇 Sunset
17:20
⏱️ Daylight
11h 32m
Wind Speed
11 km/h
Light breeze
Sunshine
9.8 hrs
Direct Sun (Cloud-free)
Humidity
80%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for San Jose
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in San Jose
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
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 December 18 averages 24.4°C with a 14% precipitation probability. Wedding/Outdoor Event Score: 100/100."
— 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
Compare Other Cities
Same date (December 18) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is San Jose Worth Visiting on December 18?
Planning a trip to San Jose on December 18? 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 24.4°C with a 14% historical precipitation risk.
✈️ Travel Logistics: Approximately 108 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 December 18 recorded in the last 30 years saw temperatures hit 27.1°C in 2024, while the coldest dropped to 14.7°C in 2018.