September weather forecast and climate
Holtville, CA

Weather in September

September, the first month of the autumn, in Holtville, is still a torrid month, with temperature in the range of an average low of 80.1°F (26.7°C) and an average high of 99.9°F (37.7°C).

Temperature

In Holtville, the average high-temperature in September marginally drops, from a scorching 106.5°F (41.4°C) in August, to a torrid 99.9°F (37.7°C). The average low-temperature, in Holtville, is 80.1°F (26.7°C).

Humidity

In Holtville, the average relative humidity is 26%.

Rainfall

In Holtville, in September, it is raining for 4.2 days, with typically 0.39" (10mm) of accumulated precipitation. Throughout the year, in Holtville, there are 29.5 rainfall days, and 2.99" (76mm) of precipitation is accumulated.

Daylight

The average length of the day in Holtville is 12.4h.

Sunshine

In Holtville, the average sunshine is 10.2h.

UV index

In September, the average daily maximum UV index in Holtville is 8. A UV Index reading of 8 to 10 represents a very high health risk from the exposure to the Sun's UV radiation for the average person.
Note: In September, the average maximum UV index of 8 translate into the following recommendations:
Take extra precautions. Protection against sun damage is required. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in September in Holtville?

The average high-temperature, in September, is 99.9°F (37.7°C), while the average low-temperature is 80.1°F (26.7°C).

What is the average humidity in September in Holtville?

The average relative humidity in September in Holtville is 26%.

How many days does it rain in September in Holtville?

In Holtville, during September, the rain falls for 4.2 days and regularly aggregates up to 0.39" (10mm) of precipitation.

How many hours of daylight does Holtville have in September?

The average length of the day in September in Holtville is 12.4h.

How many hours of sunshine does Holtville have in September?

In Holtville, California, the average sunshine in September is 10.2h.

What is the UV index intensity in September in Holtville?

In September, the average daily maximum UV index is 8. A UV Index of 8 to 10 symbolizes a very high health risk from the exposure to the Sun's UV radiation.

Average temperature in September
Holtville, CA

Average temperature in September - Holtville, CA
  • Average high temperature in September: 99.9°F

The warmest month (with the highest average high temperature) is July (107.2°F).
The month with the lowest average high temperature is December (67.3°F).

  • Average low temperature in September: 80.1°F

The month with the highest average low temperature is August (85.6°F).
The coldest month (with the lowest average low temperature) is January (50°F).

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Average pressure in September
Holtville, CA

Average pressure in September - Holtville, CA
  • Average pressure in September: 29.81"

The month with the highest atmospheric pressure is January (30.08").
The month with the lowest atmospheric pressure is June (29.77").

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Average wind speed in September
Holtville, CA

Average wind speed in September - Holtville, CA
  • Average wind speed in September: 6mph

The windiest month (with the highest average wind speed) is April (7.7mph).
The calmest months (with the lowest average wind speed) are January and August (5.5mph).

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Average humidity in September
Holtville, CA

Average humidity in September - Holtville, CA
  • Average humidity in September: 26%

The month with the highest relative humidity is December (39%).
The month with the lowest relative humidity is June (21%).

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Average rainfall in September
Holtville, CA

Average rainfall in September - Holtville, CA
  • Average rainfall in September: 0.39"

The wettest month (with the highest rainfall) is July (0.55").
The driest month (with the least rainfall) is May (0.04").

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Average rainfall days in September
Holtville, CA

Average rainfall days in September - Holtville, CA
  • Average rainfall days in September: 4.2 days

The month with the highest number of rainy days is July (6.3 days).
The month with the least rainy days is May (0.9 days).

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Average daylight in September /
Average sunshine in September
Holtville, CA

Average daylight in September / Average sunshine in September - Holtville, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.3h).
The month with the shortest days is December (Average daylight: 10h).

  • Average sunshine in September: 10.2h

The month with the most sunshine is June (Average sunshine: 12.2h).
The month with the least sunshine is December (Average sunshine: 7.1h).

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Average sunshine days in September
Holtville, CA

Average sunshine days in September - Holtville, CA
  • Average sunshine days in September: 24.4 days

The month with the most sunshine days is May (29.9 days).
The month with the least sunshine days is July (21.8 days).

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Average UV index in September
Holtville, CA

Average UV index in September - Holtville, CA
  • Average UV index in September: 8

Months with the highest UV index are July and August (UV index 9).
The month with the lowest UV index is December (UV index 4).

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Average cloud cover in September
Holtville, CA

Average cloud cover in September - Holtville, CA
  • Average cloud cover in September: 7

The month with the most cloud cover is December (Cloud cover 17).
The month with the least cloud cover is June (Cloud cover 5).

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Average visibility in September
Holtville, CA

Average visibility in September - Holtville, CA
  • Average visibility in September: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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