Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The beginning of September reveals an average high-temperature of a still warm 23°C (73.4°F), showing minimal deviation from the previous month. Throughout September, San Juan's nights cool down to an average of 16.4°C (61.5°F).Humidity
September and October, with an average relative humidity of 91%, are the most humid months.Rainfall
In San Juan, in September, during 29.5 rainfall days, 344mm (13.54") of precipitation is typically accumulated. In San Juan, during the entire year, the rain falls for 287.8 days and collects up to 2585mm (101.77") of precipitation.Daylight
The average length of the day in September is 12h and 11min.On the first day of the month, sunrise is at 05:27 and sunset at 17:45. On the last day of September, in San Juan, sunrise is at 05:24 and sunset at 17:27 CST.
Sunshine
The average sunshine in September in San Juan is 6.5h.UV index
The months with the highest UV index are January through December, with an average maximum UV index of 5. The months with the lowest UV index are January through December, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Prioritize safety - Suggestions to prevent sun damage are offered. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Enhance your sun protection with tightly woven, yet airy clothing.
Frequently asked questions
What are September temperatures in San Juan?
What is the most humid month in San Juan?
What is the average humidity in September in San Juan?
How much does it rain in San Juan in September?
How many hours of daylight does San Juan have in September?
When are sunrise and sunset in September in San Juan?
How many hours of sunshine does San Juan have in September?
When is the highest UV index in San Juan?
When is the lowest UV index in San Juan?
What is the UV index intensity in September in San Juan?
Average temperature in September
San Juan, Costa Rica
- Average high temperature in September: 23°C
The warmest month (with the highest average high temperature) is April (26°C).
The month with the lowest average high temperature is October (22.4°C).
- Average low temperature in September: 16.4°C
The month with the highest average low temperature is June (17°C).
The coldest month (with the lowest average low temperature) is January (13.8°C).
Average pressure in September
San Juan, Costa Rica
- Average pressure in September: 1011.1mbar
The month with the highest atmospheric pressure is January (1012.3mbar).
The month with the lowest atmospheric pressure is October (1010.8mbar).
Average wind speed in September
San Juan, Costa Rica
- Average wind speed in September: 4.3km/h
The windiest month (with the highest average wind speed) is February (10.7km/h).
The calmest month (with the lowest average wind speed) is September (4.3km/h).
Average humidity in September
San Juan, Costa Rica
- Average humidity in September: 91%
The months with the highest relative humidity are September and October (91%).
The months with the lowest relative humidity are February and March (75%).
Average rainfall in September
San Juan, Costa Rica
- Average rainfall in September: 344mm
The wettest month (with the highest rainfall) is October (438mm).
The driest month (with the least rainfall) is February (26mm).
Average rainfall days in September
San Juan, Costa Rica
- Average rainfall days in September: 29.5 days
The month with the highest number of rainy days is October (30.5 days).
The month with the least rainy days is February (12.2 days).
Average daylight in September /
Average sunshine in September
San Juan, Costa Rica
- Average daylight in September: 12h and 1min
The month with the longest days is June (Average daylight: 12h and 42min).
The month with the shortest days is December (Average daylight: 11h and 36min).
- Average sunshine in September: 6h and 3min
The month with the most sunshine is February (Average sunshine: 9h and 12min).
The month with the least sunshine is October (Average sunshine: 5h and 48min).
Average sunshine days in September
San Juan, Costa Rica
- Average sunshine days in September: 0.1 days
The month with the most sunshine days is March (13.5 days).
The month with the least sunshine days is September (0.1 days).
Average UV index in September
San Juan, Costa Rica
- Average UV index in September: 5
The months with the highest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 5).
The months with the lowest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 5).
Average cloud cover in September
San Juan, Costa Rica
- Average cloud cover in September: 65
The month with the most cloud cover is October (Cloud cover 68).
The month with the least cloud cover is February (Cloud cover 30).
Average visibility in September
San Juan, Costa Rica
- Average visibility in September: 6km
The months with the highest visibility are January, February and March (9km).
The months with the lowest visibility are August, September, October and November (6km).
San Juan, Costa Rica
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