September weather forecast
Mentone, CA

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Weather in September

September, the first month of the autumn in Mentone, is also a hot month, with an average temperature varying between 86.2°F (30.1°C) and 61.7°F (16.5°C).

Temperature

Mentone starts September with an average high-temperature of a still tropical 86.2°F (30.1°C), a minor shift from August's 90.3°F (32.4°C). Mentone anticipates a stark contrast in temperature during September nights, with an average low of 61.7°F (16.5°C).

Heat index

The heat index for September is evaluated at a tropical 86°F (30°C). A sense of exhaustion might occur with extended exposure and activity, potentially causing heat cramps.
When referencing the heat index, its values are suitable for shady environments and light breezes. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', gives a temperature feeling by integrating air temperature and humidity. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical 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 September, the average relative humidity is 40%.

Rainfall

In Mentone, during September, the rain falls for 2.5 days and regularly aggregates up to 0.16" (4mm) of precipitation. Throughout the year, there are 49.1 rainfall days, and 6.5" (165mm) of precipitation is accumulated.

Snowfall

January, March through December are months without snowfall.

Daylight

In Mentone, the average length of the day in September is 12h and 22min.
On the first day of September, sunrise is at 6:22 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:33 pm PDT.

Sunshine

The average sunshine in September is 10.6h.

UV index

The average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: During September, 6 as the daily maximum UV index converts into the following advice:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.

Frequently asked questions

How hot is September?

September temperatures vary between a high-temperature of 86.2°F (30.1°C) and a low-temperature of 61.7°F (16.5°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines relative humidity and air temperature, in September is evaluated at 86°F (30°C).

What is the average humidity in September?

In Mentone, the average relative humidity in September is 40%.

How much does it rain in September?

In Mentone, in September, during 2.5 rainfall days, 0.16" (4mm) of precipitation is typically accumulated.

When it does not snow?

January, March through December are months without snowfall.

How many hours of daylight does Mentone have in September?

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

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:22 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:33 pm PDT.

How long on average sun shines in September?

The average sunshine duration in September is 10.6h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Mentone, CA

Average temperature in September - Mentone, CA
  • Average high temperature in September: 86.2°F

The warmest months (with the highest average high temperature) are July and August (90.3°F).
The month with the lowest average high temperature is December (58.8°F).

  • Average low temperature in September: 61.7°F

The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).

Average pressure in September
Mentone, CA

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

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed in September
Mentone, CA

Average wind speed in September - Mentone, CA
  • Average wind speed in September: 4.7mph

The windiest month (with the highest average wind speed) is April (6.3mph).
The calmest month (with the lowest average wind speed) is September (4.7mph).

Average humidity in September
Mentone, CA

Average humidity in September - Mentone, CA
  • Average humidity in September: 40%

The month with the highest relative humidity is February (53%).
The month with the lowest relative humidity is August (37%).

Average rainfall in September
Mentone, CA

Average rainfall in September - Mentone, CA
  • Average rainfall in September: 0.16"

The wettest month (with the highest rainfall) is December (1.42").
The driest month (with the least rainfall) is June (0.04").

Average rainfall days in September
Mentone, CA

Average rainfall days in September - Mentone, CA
  • Average rainfall days in September: 2.5 days

The month with the highest number of rainy days is March (6.7 days).
The month with the least rainy days is June (1.3 days).

Average snowfall days in September
Mentone, CA

Average snowfall days in September - Mentone, 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
Mentone, CA

Average daylight in September / Average sunshine in September - Mentone, 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 month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).

Average sunshine days in September
Mentone, CA

Average sunshine days in September - Mentone, CA
  • Average sunshine days in September: 25.1 days

The month with the most sunshine days is June (28 days).
The month with the least sunshine days is February (21.3 days).

Average UV index in September
Mentone, CA

Average UV index in September - Mentone, CA
  • Average UV index in September: 6

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in September
Mentone, CA

Average cloud cover in September - Mentone, CA
  • Average cloud cover in September: 6

The months with the most cloud cover are February, March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).

Average visibility in September
Mentone, CA

Average visibility in September - Mentone, 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).

Mentone, California, USA

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