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 advent of September brings an average high-temperature of a still tropical 30.9°C (87.6°F), almost identical to the preceding month. In the month of September, San Francisco Lempa experiences an average low-temperature of 20.5°C (68.9°F).Heat index
For most parts of September, the heat index is appraised at a blisteringly hot 41°C (105.8°F). Take more preventive steps, risk of heat exhaustion and heat cramps is elevated. Long activity may culminate in heatstroke.Heat index guidelines indicate values are for light wind scenarios and shaded regions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', offers an insight into how hot it feels when we factor in moisture content. Additional elements including metabolic differences, the level of physical activity, and attire have a role in shaping the individual's temperature perception. When exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Through perspiration, the body has a natural mechanism to eliminate excessive heat via sweat evaporation. Relative humidity in excess curtails evaporation, therefore reducing heat dissipation from the body, leading to feelings of excess heat. Exceeding the body's heat disposal threshold results in a rise in body temperature and potential thermal disorders.
Humidity
The average relative humidity in September is 82%.Rainfall
In September, the rain falls for 27.5 days. Throughout September, 134mm (5.28") of precipitation is accumulated. In San Francisco Lempa, during the entire year, the rain falls for 192.2 days and collects up to 1062mm (41.81") of precipitation.Daylight
In September, the average length of the day is 12h and 12min.On the first day of the month, sunrise is at 05:44 and sunset at 18:07. On the last day of September, sunrise is at 05:45 and sunset at 17:46 CST.
Sunshine
The average sunshine in September is 8.8h.UV index
The months with the lowest UV index in San Francisco Lempa are January, June through December, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for the average person.Note: The daily maximum UV index of 6 in September interprets into the following advice:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. Remember that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. Make an effort to avoid direct sun exposure during these hours. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
How many days does it rain in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
When is the lowest UV index?
What is the UV index reading in September?
Average temperature in September
San Francisco Lempa, El Salvador
- Average high temperature in September: 30.9°C
The warmest month (with the highest average high temperature) is March (34.1°C).
The month with the lowest average high temperature is October (29.6°C).
- Average low temperature in September: 20.5°C
The month with the highest average low temperature is April (22.3°C).
The coldest month (with the lowest average low temperature) is December (18.6°C).
Average pressure in September
San Francisco Lempa, El Salvador
- Average pressure in September: 1011.5mbar
The month with the highest atmospheric pressure is January (1013.7mbar).
The months with the lowest atmospheric pressure are May and October (1011.4mbar).
Average wind speed in September
San Francisco Lempa, El Salvador
- Average wind speed in September: 4.3km/h
The windiest month (with the highest average wind speed) is January (7.5km/h).
The calmest month (with the lowest average wind speed) is June (4.2km/h).
Average humidity in September
San Francisco Lempa, El Salvador
- Average humidity in September: 82%
The month with the highest relative humidity is October (83%).
The month with the lowest relative humidity is March (59%).
Average rainfall in September
San Francisco Lempa, El Salvador
- Average rainfall in September: 134mm
The wettest month (with the highest rainfall) is May (242mm).
The driest month (with the least rainfall) is January (1mm).
Average rainfall days in September
San Francisco Lempa, El Salvador
- Average rainfall days in September: 27.5 days
The month with the highest number of rainy days is September (27.5 days).
The month with the least rainy days is January (1.5 days).
Average daylight in September /
Average sunshine in September
San Francisco Lempa, El Salvador
- Average daylight in September: 12h and 1min
The month with the longest days is June (Average daylight: 12h and 54min).
The month with the shortest days is December (Average daylight: 11h and 18min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is April (Average sunshine: 11h and 24min).
The months with the least sunshine are January and December (Average sunshine: 7h and 42min).
Average sunshine days in September
San Francisco Lempa, El Salvador
- Average sunshine days in September: 1.3 days
The month with the most sunshine days is January (29 days).
The month with the least sunshine days is September (1.3 days).
Average UV index in September
San Francisco Lempa, El Salvador
- Average UV index in September: 6
The months with the highest UV index are February, March, April and May (UV index 7).
The months with the lowest UV index are January, June, July, August, September, October, November and December (UV index 6).
Average cloud cover in September
San Francisco Lempa, El Salvador
- Average cloud cover in September: 44
The month with the most cloud cover is September (Cloud cover 44).
The months with the least cloud cover are January and December (Cloud cover 14).
Average visibility in September
San Francisco Lempa, El Salvador
- Average visibility in September: 7km
The months with the highest visibility are January, February, March, April and December (10km).
The month with the lowest visibility is September (7km).
