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
September
Weather in September
Temperature
The transition into September reveals an average high-temperature of a still moderately hot 24.5°C (76.1°F), mirroring a close resemblance to August. Alajuela records a mean low-temperature of 17.5°C (63.5°F) in September.Humidity
The average relative humidity in September is 89%.Rainfall
In September, the rain falls for 29.3 days. Throughout September, 321mm (12.64") of precipitation is accumulated. Throughout the year, there are 289.5 rainfall days, and 2506mm (98.66") of precipitation is accumulated.Daylight
In Alajuela, the average length of the day in September is 12h and 11min.On the first day of the month, sunrise is at 05:28 and sunset at 17:46. On the last day of September, sunrise is at 05:26 and sunset at 17:28 CST.
Sunshine
In Alajuela, the average sunshine in September is 7h.UV index
The months with the lowest UV index are January, February, May through December, with an average maximum UV index of 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Take precautions - Protection against sunburn is recommended. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September in Alajuela?
How much does it rain in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Alajuela have in September?
What is the month with the lowest UV index?
What is the UV index reading in September?
Average temperature in September
Alajuela, Costa Rica
- Average high temperature in September: 24.5°C
The warmest month (with the highest average high temperature) is April (28°C).
The month with the lowest average high temperature is October (23.8°C).
- Average low temperature in September: 17.5°C
The month with the highest average low temperature is May (18.3°C).
The coldest month (with the lowest average low temperature) is January (15.2°C).
Average pressure in September
Alajuela, Costa Rica
- Average pressure in September: 1011mbar
The month with the highest atmospheric pressure is January (1012.2mbar).
The month with the lowest atmospheric pressure is October (1010.8mbar).
Average wind speed in September
Alajuela, Costa Rica
- Average wind speed in September: 3.9km/h
The windiest month (with the highest average wind speed) is February (10.9km/h).
The calmest month (with the lowest average wind speed) is September (3.9km/h).
Average humidity in September
Alajuela, Costa Rica
- Average humidity in September: 89%
The month with the highest relative humidity is October (90%).
The month with the lowest relative humidity is March (71%).
Average rainfall in September
Alajuela, Costa Rica
- Average rainfall in September: 321mm
The wettest month (with the highest rainfall) is October (421mm).
The driest month (with the least rainfall) is February (25mm).
Average rainfall days in September
Alajuela, Costa Rica
- Average rainfall days in September: 29.3 days
The month with the highest number of rainy days is October (30.5 days).
The month with the least rainy days is February (12.3 days).
Average daylight in September /
Average sunshine in September
Alajuela, 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 30min).
- Average sunshine in September: 7h and 0min
The month with the most sunshine is February (Average sunshine: 9h and 24min).
The month with the least sunshine is October (Average sunshine: 6h and 12min).
Average sunshine days in September
Alajuela, Costa Rica
- Average sunshine days in September: 0.4 days
The month with the most sunshine days is February (11.9 days).
The month with the least sunshine days is September (0.4 days).
Average UV index in September
Alajuela, Costa Rica
- Average UV index in September: 5
The months with the highest UV index are March and April (UV index 6).
The months with the lowest UV index are January, February, May, June, July, August, September, October, November and December (UV index 5).
Average cloud cover in September
Alajuela, Costa Rica
- Average cloud cover in September: 59
The month with the most cloud cover is October (Cloud cover 62).
The month with the least cloud cover is February (Cloud cover 23).
Average visibility in September
Alajuela, Costa Rica
- Average visibility in September: 6km
The months with the highest visibility are January, February, March and April (9km).
The months with the lowest visibility are September and October (6km).
