What is the weather like in San Jose in September?

Expect temperatures between 17°C and 25°C with 88% average rain probability and about 8 hours of sunshine daily.

What is the weather like in San Jose in September?

San Jose in September scores 59/100 based on 30 years of climate data. Good option with minor considerations.

Who should visit San Jose in September?

September in San Jose is ideal for: Business travelers.

San Jose Weather in September | 30-Year Forecast

Avg High

25°C

Hottest around day 1

Avg Low

17°C

Coolest around day 29

Rainy Days

30days

88% avg rain chance

Sunshine

8hrs/day

Autumn season

Essential Travel Info for San Jose

🗓️ Best Time to Visit 📖 Travel Guide 🍴 Food Guide

Currency

CRC

₡ Costa Rican colón

Language

Spanish

Driving

Right side

Connect

Cable TV channels have many American Eng...

Safety

High Safety

GPI: 1.732

Travel Intelligence

Exclusive flight analytics & health data for San Jose

Smart Flight Estimator

Airport-to-Airport Logistics

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Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Moderate

42/ 100

Traffic Index

Balanced traffic

Peak Daily Arrivals

slots per day

Peak

Nov

Low

Oct

Monthly Traffic Distribution

105

Jan

Feb

107

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

118

Nov

108

Dec

Traffic Level

Low Season

Key Connections

Tocumen (PTY)

Askona ()

Puerto Jimenez (PJM)

Guatemala City La Aurora (GUA)

Santa Clara El Salvador (SAL)

Health & Safety Advisory

CDC travel health recommendations

9 Recommendations

COVID-19

All eligible travelers should be up to date with their COVID-19 vaccines. Please seeYour COVID-19 Vaccinationfor more information.

Chikungunya

All travelers should take steps to prevent mosquito bites. Chikungunya vaccination is generally not recommended. Travelers who wish to consider vaccination can visit “What to consider before traveling” on thechikungunya vaccinespage to learn more.

Hepatitis A

Recommended for unvaccinated travelers one year old or older going to Costa Rica.Infants 6 to 11 months old should also be vaccinated against Hepatitis A. The dose does not count toward the routine 2-dose series.Travelers allergic to a vaccine component should receive a single dose of immune globulin, which provides effective protection for up to 2 months depending on dosage given.Unvaccinated travelers who are over 40 years old, are immunocompromised, or have chronic medical conditions planning to depart to a risk area in less than 2 weeks should get the initial dose of vaccine and at the same appointment receive immune globulin.

Hepatitis B

Recommended for unvaccinated travelers younger than 60 years old traveling to Costa Rica. Unvaccinated travelers 60 years and older may get vaccinated before traveling to Costa Rica.

Malaria

CDC recommends that travelers going to certain areas of Costa Rica take prescription medicine to prevent malaria. Depending on the medicine you take, you will need to start taking this medicine multiple days before your trip, as well as during and after your trip. Talk to your doctor about which malaria medication you should take.Transmission areasPresent in the provinces of Alajuela and LimónRare to no transmission in other parts of the countryDrug resistanceNoneSpeciesP. falciparum(86%)P. vivax(14%)Recommended chemoprophylaxisAlajuela and Limón Provinces: Atovaquone-proguanil, chloroquine, doxycycline, mefloquine, tafenoquine2All other areas: No chemoprophylaxis recommended (insect bite precautions and mosquito avoidance only)4Updated April 23, 2025See footnotes

Measles

Cases of measles are on the rise worldwide. Travelers are at risk of measles if they have not been fully vaccinated at least two weeks prior to departure, or have not had measles in the past, and travel internationally to areas where measles is spreading.All international travelers should be fully vaccinated against measles with the measles-mumps-rubella (MMR) vaccine, including an early dose for infants 6–11 months, according toCDC’s measles vaccination recommendations for international travel.

+3 more

Source: CDC Travelers' Health

View Complete Health Guide

Is September a Good Time to Visit San Jose?

👌Good option with minor considerations(59/100)

Short Answer

San Jose during September means embracing the rain (88%, 12mm typical). Some activities may be affected, but the lush landscapes and fewer tourists can be rewarding.

Decision Factors

High rainfall period

88% rain probability, 12.3mm average

Vaccinations required

Yellow Fever

Seismically active region

23 earthquakes recorded in this month (30-year data)

Very high humidity

90% average humidity

Ideal temperature range

24.5°C - perfect for sightseeing and outdoor activities

Health precautions needed

Be aware of: Leptospirosis, Melioidosis, Chagas disease (American Trypanosomiasis)

Good For

💼
Business travelers
Climate-controlled meetings unaffected by weather

Who Should Avoid

👴
Elderly travelers
90% humidity creates difficult conditions
🥾
Outdoor enthusiasts
88% rain probability disrupts outdoor activities
📸
Photographers
89% cloud cover limits natural light opportunities
💑
Honeymoon couples
Wedding score only 46/100 - better months available

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,San Jose in September averages 25°C with 88% precipitation probability."

📊 Source: 30YearWeather.com🛰️ Data: NASA POWER (1991-2021)View Methodology →

Frequently Asked Questions: San Jose in September

What are the temperatures in San Jose in September?

Daytime highs average 25°C, nights drop to 17°C. Temperatures remain fairly consistent.

How many rainy days in San Jose in September?

Expect around 30 days with measurable rainfall. Definitely pack rain gear.

What to wear in San Jose in September?

Comfortable casual wear with a light jacket for evenings.

Is September peak season in San Jose?

This is off-peak season. Expect lower prices and fewer crowds.

San Jose Weather in September

San Jose September Weather Calendar