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 arrival of September marks a slight shift to an average high-temperature of a still warm 80.8°F (27.1°C) from August's 81.9°F (27.7°C). The month of September records an average low-temperature of 63.3°F (17.4°C) in Lake San Marcos.Heat index
September's heat index is calculated to be 82.4°F (28°C). Prolonged activity during exposure might result in a state of fatigue and cause heat cramps.Given the heat index, its values are aligned with shaded sites and gentle winds. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is an estimation of the warmth sensation when considering humidity levels. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Realize that direct exposure to sunlight can augment the felt heat, leading to a potential increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Young ones often disregard the necessity to rest and hydrate. Thirst usually indicates advanced dehydration - hence, it is key to stay hydrated, particularly during ongoing physical activities.
Humidity
The average relative humidity in September in Lake San Marcos is 62%.Rainfall
In Lake San Marcos, California, in September, during 2.7 rainfall days, 0.16" (4mm) of precipitation is typically accumulated. In Lake San Marcos, during the entire year, the rain falls for 52.1 days and collects up to 6.1" (155mm) of precipitation.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:23 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:34 pm PDT.
Sunshine
In September, the average sunshine is 10.4h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index in Lake San Marcos. A UV Index reading of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The average daily UV index of 6 in September transforms into the following instructions:
Employ safeguards and advocate sun safety protocols. Shielding against skin and eye damage is crucial. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Lake San Marcos in September?
What is the average humidity in September in Lake San Marcos?
How many days does it rain in September in Lake San Marcos?
What is the average length of the day in September in Lake San Marcos?
What time are sunrise and sunset in September in Lake San Marcos?
How many hours of sunshine does Lake San Marcos have in September?
What are the months with the highest UV index in Lake San Marcos?
What is the UV index intensity in September in Lake San Marcos?
Average temperature in September
Lake San Marcos, CA
- Average high temperature in September: 80.8°F
The warmest month (with the highest average high temperature) is August (81.9°F).
The months with the lowest average high temperature are February and December (63.3°F).
- Average low temperature in September: 63.3°F
The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is February (48°F).
Average pressure in September
Lake San Marcos, 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
Lake San Marcos, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is April (5.7mph).
The calmest month (with the lowest average wind speed) is October (4.4mph).
Average humidity in September
Lake San Marcos, CA
- Average humidity in September: 62%
The month with the highest relative humidity is May (70%).
The month with the lowest relative humidity is November (56%).
Average rainfall in September
Lake San Marcos, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is December (1.22").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Lake San Marcos, CA
- Average rainfall days in September: 2.7 days
The month with the highest number of rainy days is March (7.8 days).
The month with the least rainy days is June (1.2 days).
Average daylight in September /
Average sunshine in September
Lake San Marcos, 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 6min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).
Average sunshine days in September
Lake San Marcos, CA
- Average sunshine days in September: 25.3 days
The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is February (20 days).
Average UV index in September
Lake San Marcos, 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, March, November and December (UV index 4).
Average cloud cover in September
Lake San Marcos, CA
- Average cloud cover in September: 10
The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 7).
Average visibility in September
Lake San Marcos, 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).
Lake San Marcos, California, USA
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