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
La Mesa's entry into September measures an average high-temperature of a still moderately hot 81.5°F (27.5°C), closely parallel to the preceding month. La Mesa's nighttime temperature during September is consistently averaged at an enjoyable 64.4°F (18°C).Heat index
The heat index value during September is appraised at 84.2°F (29°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.For clarity, heat index numbers account for light winds and areas under shade. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'real feel', binds temperature metrics with humidity values to give a sense of the actual warmth. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
Humidity
The average relative humidity in September in La Mesa is 61%.Rainfall
In September, the rain falls for 3.7 days. Throughout September, 0.28" (7mm) of precipitation is accumulated. Throughout the year, there are 54.5 rainfall days, and 6.57" (167mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 22min.On the first day of September in La Mesa, sunrise is at 6:23 am and sunset at 7:12 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:33 pm PDT.
Sunshine
In September, the average sunshine in La Mesa is 10.3h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index in La Mesa. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV radiation for the average person.Note: In September, the maximum UV index of 6 suggests this advice:
Enforce precautions and stick to sun safety measures. Preservation from skin and eye damage is essential. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Frequently asked questions
What is the average September temperature in La Mesa?
What is the average humidity in September in La Mesa?
How much does it rain in La Mesa in September?
What is the average length of the day in September in La Mesa?
When is the sunrise / sunset in September in La Mesa?
How many hours of sunshine does La Mesa have in September?
What is the month with the highest UV index in La Mesa?
What is the UV index reading in September in La Mesa?
Average temperature in September
La Mesa, CA
- Average high temperature in September: 81.5°F
The warmest month (with the highest average high temperature) is August (82.6°F).
The month with the lowest average high temperature is December (64.2°F).
- Average low temperature in September: 64.4°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (48.7°F).
Average pressure in September
La Mesa, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
La Mesa, CA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is April (5.7mph).
The calmest month (with the lowest average wind speed) is October (4.5mph).
Average humidity in September
La Mesa, CA
- Average humidity in September: 61%
The month with the highest relative humidity is May (68%).
The month with the lowest relative humidity is November (55%).
Average rainfall in September
La Mesa, CA
- Average rainfall in September: 0.28"
The wettest month (with the highest rainfall) is February (1.3").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
La Mesa, CA
- Average rainfall days in September: 3.7 days
The month with the highest number of rainy days is March (7.8 days).
The month with the least rainy days is June (1.4 days).
Average daylight in September /
Average sunshine in September
La Mesa, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 2min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
La Mesa, CA
- Average sunshine days in September: 24.6 days
The month with the most sunshine days is June (28.1 days).
The month with the least sunshine days is February (21 days).
Average UV index in September
La Mesa, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover in September
La Mesa, CA
- Average cloud cover in September: 11
The month with the most cloud cover is March (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 8).
Average visibility in September
La Mesa, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
La Mesa, California, USA
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