Temperatures in September
It's warm in September in Costa Rica with an average temperature of 28°C. Temperatures this month range from a low of 27°C to a high of 29°C. At night, you can expect temperatures between 15°C and 16°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Costa Rica in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Costa Rica with hot temperatures, averaging around 29°C during the day and nights close to 16°C. Plenty of days with a chance of precipitation.
Since temperatures can differ between day and night, it’s a good idea to dress in layers.
Mid-September
By mid-September, the average daytime temperature drops to around 28°C, with nights close to 16°C. The chance of precipitation is high during this period.
Temperatures vary between day and night, so it’s smart to wear layers.
End of September
By the end of September, the average daytime temperature in Costa Rica will be around 28°C, with nights close to 16°C. There’s a significant chance of many days with precipitation.
As it gets cooler in the evening, it’s best to wear layers.
Precipitation in September
In September, there is an average of 272 mm of precipitation, spread over 25 days. The wind speed is around 3 Bft, mostly coming from the Southeast.
With an average precipitation chance of 82% this month, rainy days are almost inevitable.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Costa Rica. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Costa Rica in September |
London | ||
|---|---|---|---|
 Average Temperature |
28°C | 20°C | |
 High Temp |
29°C | 22°C | |
| Low Temp |
27°C | 17°C | |
 Total Precipitation |
272 mm | 44 mm | |
| Rainy Days |
25 days | 8 days | |
August
UV index
The UV index is a maximum of 9 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?
After some sun? Then September isn’t the best time to be in Costa Rica. The temperature is pleasant, but there’s too much chance of rain this month.
Temperature records for Costa Rica in September
With 34°C, Costa Rica hit the highest temperature in the last 10 years in September 2021. The lowest daytime temperature in this month was 22°C in 2014. The extreme night temperatures ranged from a low of 10°C to a high of 19°C.
Check out the climate of Costa Rica for all months and discover the best travel time
Curious about the climate in other parts of Mexico? Check out the weather and climate in places like Cancún, Mexico City, Playa del Carmen, or have a look at other destinations in Mexico.
Daily Temperature in September in Costa Rica
This chart shows the average daily temperatures, both day and night, for each day in September in Costa Rica, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Costa Rica
The chart below shows the average daily precipitation in September for Costa Rica, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown 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 rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 25 days of rain 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 years.
Total Precipitation in September in Costa Rica Over the Years
This chart shows the average precipitation in September in Costa Rica, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Costa Rica
Click on a specific day in September for detailed info on the typical 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
