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 snowfall 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
At the onset of September, Sierra Heights records an average high-temperature of a still tropical 88.3°F (31.3°C), showing little deviation from the preceding month. A significant drop from the day's peak to an average low-temperature of 63.9°F (17.7°C) is noted during the nights in September.Heat index
For most parts of September, the heat index is computed to be a hot 89.6°F (32°C). Exhaustion becomes probable with enduring exposure and activity, potentially causing heat cramps.Be advised, the heat index considers values for conditions in shade and with a light breeze. The heat index values could be amplified by up to 15 Fahrenheit (8 Celsius) degrees in direct sunlight.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. Being under direct sunshine can magnify the heat experience, possibly pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Humidity
In Sierra Heights, the average relative humidity in September is 42%.Rainfall
In Sierra Heights, in September, it is raining for 2.4 days, with typically 0.12" (3mm) of accumulated precipitation. Throughout the year, there are 48.1 rainfall days, and 6.89" (175mm) of precipitation is accumulated.Snowfall
In Sierra Heights, snow does not fall in January, March through December.Daylight
In September, the average length of the day is 12h and 22min.On the first day of September, sunrise is at 6:23 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:34 pm PDT.
Sunshine
In September, the average sunshine is 10.7h.UV index
In Sierra Heights, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the average person.Note: In September, a regular UV index of 6 translates into these guidelines:
Endorse precautions and be consistent with sun safety guidelines. Preventing sunburn is paramount. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Sierra Heights have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Sierra Heights, CA
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is August (92.1°F).
The month with the lowest average high temperature is December (60.8°F).
- Average low temperature in September: 63.9°F
The month with the highest average low temperature is August (67.3°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in September
Sierra Heights, CA
- Average pressure in September: 29.87"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Sierra Heights, CA
- Average wind speed in September: 4.5mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Sierra Heights, CA
- Average humidity in September: 42%
The months with the highest relative humidity are February, March and May (52%).
The month with the lowest relative humidity is August (39%).
Average rainfall in September
Sierra Heights, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (1.57").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Sierra Heights, CA
- Average rainfall days in September: 2.4 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in September
Sierra Heights, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Sierra Heights, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 4min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in September
Sierra Heights, CA
- Average sunshine days in September: 25.9 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21.1 days).
Average UV index in September
Sierra Heights, CA
- Average UV index in September: 6
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Sierra Heights, CA
- Average cloud cover in September: 6
The months with the most cloud cover are February, March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in September
Sierra Heights, 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).
Sierra Heights, California, USA
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