September weather forecast
Alpine Heights, CA

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Weather in September

September, the first month of the autumn in Alpine Heights, is still a warm month, with an average temperature varying between 62.8°F (17.1°C) and 84.2°F (29°C).

Temperature

September's presence records an average high-temperature of a moderately hot 84.2°F (29°C), closely mirroring August's climate. Throughout the month of September, Alpine Heights expects an average low of 62.8°F (17.1°C).

Heat index

In September, the heat index is evaluated at a hot 86°F (30°C). If one sustains activity during exposure, it could lead to a sense of fatigue, with a chance of heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is an estimation of the warmth sensation when considering humidity levels. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. Understand that direct sun rays can influence the weather's impact, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.

Humidity

In September, the average relative humidity is 53%.

Rainfall

In Alpine Heights, in September, it is raining for 5.5 days, with typically 0.51" (13mm) of accumulated precipitation. In Alpine Heights, during the entire year, the rain falls for 62 days and collects up to 6.38" (162mm) of precipitation.

Daylight

In Alpine Heights, the average length of the day in September is 12h and 22min.
On the first day of the month, sunrise is at 6:22 am and sunset at 7:11 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:32 pm PDT.

Sunshine

The average sunshine in September is 10.4h.

UV index

The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index of 6 during September translates into the following directions:
Inhibit overexposure. Warding off sun damage is of utmost importance. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Updated: Jul 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot does it get in September?

During September, Alpine Heights experiences an average high-temperature of 84.2°F (29°C) and a low-temperature of 62.8°F (17.1°C). In September, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 86°F (30°C).

What is the average humidity in September?

The average relative humidity in September is 53%.

How much does it rain in Alpine Heights in September?

In Alpine Heights, in September, during 5.5 rainfall days, 0.51" (13mm) of precipitation is typically accumulated.

How many hours of daylight does Alpine Heights have in September?

In September, the average day length is 12h and 22min.

When is the sunrise / sunset in September in Alpine Heights?

On the first day of September, sunrise is at 6:22 am and sunset at 7:11 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:32 pm PDT.

How long on average sun shines in September?

In Alpine Heights, the average sunshine duration in September is 10.4h.

What are the months with the highest UV index?

June through September, with an average maximum UV index of 6, are months with the highest UV index.

What is the UV index reading in September?

In Alpine Heights, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Alpine Heights, CA

Average temperature in September - Alpine Heights, CA
  • Average high temperature in September: 84.2°F

The warmest month (with the highest average high temperature) is August (87.3°F).
The month with the lowest average high temperature is December (61.3°F).

  • Average low temperature in September: 62.8°F

The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (44.2°F).

Average pressure in September
Alpine Heights, CA

Average pressure in September - Alpine Heights, CA
  • Average pressure in September: 29.86"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

Average wind speed in September
Alpine Heights, CA

Average wind speed in September - Alpine Heights, CA
  • Average wind speed in September: 4.1mph

The windiest month (with the highest average wind speed) is May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.1mph).

Average humidity in September
Alpine Heights, CA

Average humidity in September - Alpine Heights, CA
  • Average humidity in September: 53%

The month with the highest relative humidity is May (62%).
The month with the lowest relative humidity is November (51%).

Average rainfall in September
Alpine Heights, CA

Average rainfall in September - Alpine Heights, CA
  • Average rainfall in September: 0.51"

The wettest month (with the highest rainfall) is February (0.94").
The driest month (with the least rainfall) is June (0.08").

Average rainfall days in September
Alpine Heights, CA

Average rainfall days in September - Alpine Heights, CA
  • Average rainfall days in September: 5.5 days

The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (1.5 days).

Average daylight in September /
Average sunshine in September
Alpine Heights, CA

Average daylight in September / Average sunshine in September - Alpine Heights, 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 months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).

Average sunshine days in September
Alpine Heights, CA

Average sunshine days in September - Alpine Heights, CA
  • Average sunshine days in September: 21.8 days

The month with the most sunshine days is June (27.5 days).
The month with the least sunshine days is July (19.4 days).

Average UV index in September
Alpine Heights, CA

Average UV index in September - Alpine Heights, 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 November and December (UV index 3).

Average cloud cover in September
Alpine Heights, CA

Average cloud cover in September - Alpine Heights, CA
  • Average cloud cover in September: 8

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 6).

Average visibility in September
Alpine Heights, CA

Average visibility in September - Alpine 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).

Alpine Heights, California, USA

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