Average weather for Costa Rica in September
It's warm in September in Costa Rica with an average temperature of 27°C. Temperatures this month range from a low of 26°C to a high of 28°C. At night, you can expect temperatures between 18°C and 20°C.
Start of September
The month of September starts in Costa Rica with hot temps, averaging around 28°C during the day and nights around 20°C. There are plenty of days with a good chance of precipitation.
With the temperature difference between day and night, it’s smart to wear layers.
Mid September
By mid-September, daytime temps stay steady at around 28°C, with nights around 20°C. There’s a high chance of precipitation during this time.
Since it cools down at night, it’s a good idea to wear layers.
End of September
By the end of September, the average daytime temperature in Costa Rica is around 28°C, while nighttime temps are about 19°C. There’s a significant chance of many days with precipitation.
Because temperatures drop in the evening, wearing layers is recommended.
In September, there is an average of 284 mm of precipitation, spread over 21 days. The wind speed is around 4 Bft, mostly coming from the South.
Costa Rica in September |
New York | ||
|---|---|---|---|
 Average temperature |
27°C | 27°C | |
 Max. temperature |
28°C | 31°C | |
| Min. temperature |
26°C | -5°C | |
 Total precipitation |
284 mm | 57 mm | |
| Rainy days |
21 days | 9 days | |
August
UV index
The UV index is a maximum of 8 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
Is September a good time to visit Costa Rica?
Looking for sun? September isn’t a good month to be in Costa Rica. The temperature is nice, but there’s too much chance of rain.
The hurricane season in Costa Rica runs from June to November.
Temperature records
With 31°C in 2015, Costa Rica reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 23°C in 2014. The extreme nighttime temperatures ranged from a lowest recorded value of 10°C to a highest value of 23°C.
Check out the climate of Costa Rica for all months and discover the best travel time
The climate in Costa Rica is based on weather data from San José. Other spots might have different weather. You can check out all destinations in Costa Rica to get the full picture of the climate.
Daily Temperature in September in Costa Rica
This chart shows the average daily high and low temperatures in September for Costa Rica, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.
Daily Precipitation in September in Costa Rica
The chart below shows the average daily precipitation in September for Costa Rica, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for September, you can expect about 21 days of precipitation in Costa Rica.
Daily UV index in September in Costa Rica
This chart shows the average daily UV index in September in Costa Rica, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Costa Rica over the years
This chart shows the average temperature in September in Costa Rica, measured in degrees Celsius, over the past few years.
Total precipitation in September in Costa Rica over the years
This chart shows the average precipitation in September in Costa Rica, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Daily weather in September for Costa Rica
Click on any day in September to get detailed info about the usual weather on that day in Costa Rica. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Costa Rica
Have you been to Costa Rica in September?
Share your weather experience in September in Costa Rica.
Average weather in Costa Rica by month
Click on a month below to see detailed weather info for Costa Rica. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Costa Rica for all months at once
