September weather forecast
Rancho Bernardo, CA

Weather in September

September, the first month of the autumn in Rancho Bernardo, is still a warm month, with temperature in the range of an average low of 63.1°F (17.3°C) and an average high of 82.6°F (28.1°C).

Temperature

In September, the average high-temperature is almost the same as in August - a still moderately hot 82.6°F (28.1°C). In September, the average low-temperature is 63.1°F (17.3°C).

Heat index

The average heat index in September is calculated to be a hot 86°F (30°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'real feel', 'felt air temperature', or 'apparent temperature', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Additional factors like activity, metabolic differences, wind, and differences in body mass, height, and shape affect individual temperature impact. 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 particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

The average relative humidity in September in Rancho Bernardo, California, is 60%.

Rainfall

In Rancho Bernardo, California, during 3.8 rainfall days, 0.31" (8mm) of precipitation is typically accumulated. Throughout the year, there are 54.7 rainfall days, and 8.15" (207mm) of precipitation is accumulated.

Daylight

The average length of the day in September in Rancho Bernardo is 12h and 22min.
On the first day of the month, sunrise is at 6:22 am and sunset at 7:13 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:34 pm PDT.

Sunshine

The average sunshine in September in Rancho Bernardo is 10.3h.

UV index

June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for average individuals.
Note: The daily maximum UV index of 6 in September interpret into the following advice:
Take precautions and utilize sun safety practices. Protection against skin and eye 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. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
[Resources]

FAQ

What is the temperature in September in Rancho Bernardo?

The average high-temperature, in September, in Rancho Bernardo, California, is 82.6°F (28.1°C), while the average low-temperature is 63.1°F (17.3°C). in September, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines relative humidity and air temperature, is calculated to be 86°F (30°C).

What is the average humidity in September in Rancho Bernardo?

The average relative humidity in September in Rancho Bernardo, California, is 60%.

How much does it rain in Rancho Bernardo in September?

In Rancho Bernardo, in September, it is raining for 3.8 days, with typically 0.31" (8mm) of accumulated precipitation.

How many hours of daylight does Rancho Bernardo have in September?

The average day length in September is 12h and 22min.

What time are sunrise and sunset in September in Rancho Bernardo?

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 6:41 am and sunset at 6:34 pm PDT.

How long on average sun shines in September in Rancho Bernardo?

The average sunshine duration in September in Rancho Bernardo, California, is 10.3h.

When is the highest UV index in Rancho Bernardo?

The months with the highest UV index in Rancho Bernardo, California, are June through September, with an average maximum UV index of 6.

What is the UV index reading in September in Rancho Bernardo?

In September, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health threat from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Rancho Bernardo, CA

Average temperature in September - Rancho Bernardo, CA
  • Average high temperature in September: 82.6°F

The warmest month (with the highest average high temperature) is August (84.2°F).
The month with the lowest average high temperature is December (63.9°F).

  • Average low temperature in September: 63.1°F

The month with the highest average low temperature is August (64.4°F).
The coldest month (with the lowest average low temperature) is February (47.1°F).

[Resources]

Average pressure in September
Rancho Bernardo, CA

Average pressure in September - Rancho Bernardo, CA
  • Average pressure in September: 29.87"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are June and September (29.87"Hg).

[Resources]

Average wind speed in September
Rancho Bernardo, CA

Average wind speed in September - Rancho Bernardo, CA
  • Average wind speed in September: 4.3mph

The windiest month (with the highest average wind speed) is April (5.5mph).
The calmest months (with the lowest average wind speed) are September and October (4.3mph).

[Resources]

Average humidity in September
Rancho Bernardo, CA

Average humidity in September - Rancho Bernardo, CA
  • Average humidity in September: 60%

The month with the highest relative humidity is May (68%).
The month with the lowest relative humidity is November (54%).

[Resources]

Average rainfall in September
Rancho Bernardo, CA

Average rainfall in September - Rancho Bernardo, CA
  • Average rainfall in September: 0.31"

The wettest month (with the highest rainfall) is February (1.61").
The driest month (with the least rainfall) is June (0.08").

[Resources]

Average rainfall days in September
Rancho Bernardo, CA

Average rainfall days in September - Rancho Bernardo, CA
  • Average rainfall days in September: 3.8 days

The month with the highest number of rainy days is March (7.2 days).
The month with the least rainy days is June (1.6 days).

[Resources]

Average daylight in September /
Average sunshine in September
Rancho Bernardo, CA

Average daylight in September / Average sunshine in September - Rancho Bernardo, CA
  • Average daylight in September: 12h and 22min

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 1min).

  • Average sunshine in September: 10h and 18min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 6h and 42min).

[Resources]

Average sunshine days in September
Rancho Bernardo, CA

Average sunshine days in September - Rancho Bernardo, CA
  • Average sunshine days in September: 23.9 days

The month with the most sunshine days is June (27 days).
The month with the least sunshine days is February (21.2 days).

[Resources]

Average UV index in September
Rancho Bernardo, CA

Average UV index in September - Rancho Bernardo, 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, November and December (UV index 4).

[Resources]

Average cloud cover in September
Rancho Bernardo, CA

Average cloud cover in September - Rancho Bernardo, CA
  • Average cloud cover in September: 10

The month with the most cloud cover is March (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 7).

[Resources]

Average visibility in September
Rancho Bernardo, CA

Average visibility in September - Rancho Bernardo, 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).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location