September weather forecast
Larkspur, CA

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Weather in September

September, the first month of the autumn in Larkspur, is still a pleasant month, with an average temperature varying between 56.1°F (13.4°C) and 72.3°F (22.4°C).

Temperature

The warmest period tends to be September, when average temperatures fluctuate between a high of 72.3°F (22.4°C) and a low of 56.1°F (13.4°C).

Humidity

In September, the average relative humidity is 71%.

Rainfall

The months with the least rainfall are June through September Rain falls for 1.7 days and accumulates 0.04" (1mm) of rain.

Daylight

The average length of the day in September is 12h and 25min.
On the first day of September, sunrise is at 6:40 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:54 pm PDT.

Sunshine

In September, the average sunshine is 10.4h.

UV index

The months with the highest UV index are April, June through September, with an average maximum UV index of 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.
Note: In September, a daily UV index of 5 turns into the following recommendations:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.

Frequently asked questions

What month is the hottest?

In Larkspur, the average highest temperatures are observed in September, with a high of 72.3°F (22.4°C) and a low of 56.1°F (13.4°C).

What is the usual temperature for Larkspur in September?

An average high-temperature, in September, in Larkspur, is 72.3°F (22.4°C) and the average low-temperature is 56.1°F (13.4°C).

What is the average humidity in September?

In Larkspur, the average relative humidity in September is 71%.

What is the driest month?

June through September are months with the least rain when the rain falls for 1.7 days and typically aggregates up to 0.04" (1mm) of rain.

How much does it rain in September?

In Larkspur, in September, it is raining for 1.7 days, with typically 0.04" (1mm) of accumulated precipitation.

What is the average length of the day in September?

The average day length in September in Larkspur is 12h and 25min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:40 am and sunset at 7:38 pm. On the last day of the month, in Larkspur, sunrise is at 7:05 am and sunset at 6:54 pm PDT.

How long on average sun shines in September in Larkspur?

In September, the average sunshine duration is 10.4h.

What are the months with the highest UV index?

April, June through September, with an average maximum UV index of 5, are months with the highest UV index.

How high is the UV index in September?

In Larkspur, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to 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
Larkspur, CA

Average temperature in September - Larkspur, CA
  • Average high temperature in September: 72.3°F

The warmest month (with the highest average high temperature) is September (72.3°F).
The month with the lowest average high temperature is December (55.4°F).

  • Average low temperature in September: 56.1°F

The month with the highest average low temperature is September (56.1°F).
The coldest month (with the lowest average low temperature) is December (45.3°F).

Average pressure in September
Larkspur, CA

Average pressure in September - Larkspur, CA
  • Average pressure in September: 29.92"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).

Average wind speed in September
Larkspur, CA

Average wind speed in September - Larkspur, CA
  • Average wind speed in September: 5.9mph

The windiest month (with the highest average wind speed) is May (7.8mph).
The calmest months (with the lowest average wind speed) are October and November (5.5mph).

Average humidity in September
Larkspur, CA

Average humidity in September - Larkspur, CA
  • Average humidity in September: 71%

The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is October (68%).

Average rainfall in September
Larkspur, CA

Average rainfall in September - Larkspur, CA
  • Average rainfall in September: 0.04"

The wettest month (with the highest rainfall) is February (0.87").
The driest months (with the least rainfall) are June, July, August and September (0.04").

Average rainfall days in September
Larkspur, CA

Average rainfall days in September - Larkspur, CA
  • Average rainfall days in September: 1.7 days

The month with the highest number of rainy days is March (8.8 days).
The months with the least rainy days are June and August (1.2 days).

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

Average daylight in September / Average sunshine in September - Larkspur, CA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 10h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in September
Larkspur, CA

Average sunshine days in September - Larkspur, CA
  • Average sunshine days in September: 26 days

The month with the most sunshine days is June (26.4 days).
The month with the least sunshine days is March (20.7 days).

Average UV index in September
Larkspur, CA

Average UV index in September - Larkspur, CA
  • Average UV index in September: 5

The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).

Average cloud cover in September
Larkspur, CA

Average cloud cover in September - Larkspur, CA
  • Average cloud cover in September: 19

The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is September (Cloud cover 19).

Average visibility in September
Larkspur, CA

Average visibility in September - Larkspur, 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).

Larkspur, California, USA

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