September weather forecast
Sebastopol, CA

Share

Weather in September

September, the first month of the autumn in Sebastopol, is still a warm month, with temperature in the range of an average low of 54.7°F (12.6°C) and an average high of 79°F (26.1°C).

Temperature

The advent of September brings an average high-temperature of a still moderately hot 79°F (26.1°C), almost identical to the preceding month. Sebastopol notes a substantial temperature decline from the daytime peaks throughout September, with an average nighttime temperature of 54.7°F (12.6°C).

Humidity

With an average relative humidity of 63%, September is the least humid month.

Rainfall

In September, the rain falls for 2.8 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. Throughout the year, there are 72.8 rainfall days, and 12.01" (305mm) of precipitation is accumulated.

Daylight

In September, the average length of the day in Sebastopol is 12h and 25min.
On the first day of September in Sebastopol, sunrise is at 6:41 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:55 pm PDT.

Sunshine

In September, the average sunshine in Sebastopol is 11h.

UV index

In Sebastopol, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: The maximum daily UV index of 5 during September translates into the following directions:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
[Resources]

Frequently asked questions

What are September temperatures in Sebastopol?

The high-temperature, in September, in Sebastopol, records 79°F (26.1°C), while the low-temperature is 54.7°F (12.6°C).

What is the least humid month in Sebastopol?

With an average relative humidity of 63%, September is the least humid month in Sebastopol.

What is the average humidity in September in Sebastopol?

In Sebastopol, the average relative humidity in September is 63%.

How much does it rain in Sebastopol in September?

In Sebastopol, in September, it is raining for 2.8 days, with typically 0.12" (3mm) of accumulated precipitation.

What is the average length of the day in September in Sebastopol?

The average day length in September in Sebastopol, California, is 12h and 25min.

When is the sunrise / sunset in September in Sebastopol?

In September, on the first day of the month, sunrise is at 6:41 am and sunset at 7:40 pm. On the last day of the month, in Sebastopol, sunrise is at 7:06 am and sunset at 6:55 pm PDT.

How long on average sun shines in September in Sebastopol?

The average sunshine duration in September in Sebastopol is 11h.

How high is the UV index in September in Sebastopol?

In Sebastopol, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health threat 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
Sebastopol, CA

Average temperature in September - Sebastopol, CA
  • Average high temperature in September: 79°F

The warmest month (with the highest average high temperature) is August (79.7°F).
The month with the lowest average high temperature is December (55.6°F).

  • Average low temperature in September: 54.7°F

The months with the highest average low temperature are August and September (54.7°F).
The coldest month (with the lowest average low temperature) is December (41.9°F).

[Resources]

Average pressure in September
Sebastopol, CA

Average pressure in September - Sebastopol, 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).

[Resources]

Average wind speed in September
Sebastopol, CA

Average wind speed in September - Sebastopol, CA
  • Average wind speed in September: 5.2mph

The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).

[Resources]

Average humidity in September
Sebastopol, CA

Average humidity in September - Sebastopol, CA
  • Average humidity in September: 63%

The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (63%).

[Resources]

Average rainfall in September
Sebastopol, CA

Average rainfall in September - Sebastopol, CA
  • Average rainfall in September: 0.12"

The wettest month (with the highest rainfall) is February (2.64").
The driest months (with the least rainfall) are July and August (0.04").

[Resources]

Average rainfall days in September
Sebastopol, CA

Average rainfall days in September - Sebastopol, CA
  • Average rainfall days in September: 2.8 days

The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.8 days).

[Resources]

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

Average daylight in September / Average sunshine in September - Sebastopol, 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 30min).

  • Average sunshine in September: 11h and 0min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).

[Resources]

Average sunshine days in September
Sebastopol, CA

Average sunshine days in September - Sebastopol, CA
  • Average sunshine days in September: 26.5 days

The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (17.1 days).

[Resources]

Average UV index in September
Sebastopol, CA

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

The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).

[Resources]

Average cloud cover in September
Sebastopol, CA

Average cloud cover in September - Sebastopol, CA
  • Average cloud cover in September: 10

The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 9).

[Resources]

Average visibility in September
Sebastopol, CA

Average visibility in September - Sebastopol, 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]

Sebastopol, California, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location