September weather forecast
Castroville, CA

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Weather in September

The first month of the autumn, September, is still a warm month in Castroville, California, with an average temperature varying between 76.5°F (24.7°C) and 54.5°F (12.5°C).

Temperature

The shift into September reveals an average high-temperature of a still moderately hot 76.5°F (24.7°C), closely mirroring August's climate. Castroville reports a steady low-temperature average of 54.5°F (12.5°C) throughout September, revealing a large deviation from the daytime high.

Humidity

The average relative humidity in September is 67%.

Rainfall

June through September are months with the least rain in Castroville when the rain falls for 2.1 days and typically aggregates up to 0.04" (1mm) of rain.

Daylight

The average length of the day in September is 12h and 24min.
On the first day of September, sunrise is at 6:38 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.

Sunshine

In September, the average sunshine is 11.2h.

UV index

The months with the highest UV index are June through September, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Take necessary precautions - Protection from skin and eye injury is mandatory. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.

Frequently asked questions

What are September temperatures?

Castroville in September has an average high-temperature of 76.5°F (24.7°C) and an average low-temperature of 54.5°F (12.5°C).

What is the average humidity in September?

In Castroville, California, the average relative humidity in September is 67%.

What is the driest month?

June through September are months with the least rain when the rain falls for 2.1 days and typically aggregates up to 0.04" (1mm) of rain.

How much does it rain in Castroville in September?

In Castroville, in September, during 2.1 rainfall days, 0.04" (1mm) of precipitation is typically accumulated.

How many hours of daylight does Castroville have in September?

The average day length in September is 12h and 24min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:38 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.

How many hours of sunshine does Castroville have in September?

In September, the average sunshine duration is 11.2h.

What are the months with the highest UV index in Castroville?

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

How high is the UV index in September?

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Castroville, CA

Average temperature in September - Castroville, CA
  • Average high temperature in September: 76.5°F

The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (57.6°F).

  • Average low temperature in September: 54.5°F

The month with the highest average low temperature is September (54.5°F).
The coldest month (with the lowest average low temperature) is December (43.7°F).

Average pressure in September
Castroville, CA

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

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).

Average wind speed in September
Castroville, CA

Average wind speed in September - Castroville, CA
  • Average wind speed in September: 4.9mph

The windiest month (with the highest average wind speed) is May (6.5mph).
The calmest month (with the lowest average wind speed) is September (4.9mph).

Average humidity in September
Castroville, CA

Average humidity in September - Castroville, CA
  • Average humidity in September: 67%

The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is October (66%).

Average rainfall in September
Castroville, CA

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

The wettest month (with the highest rainfall) is December (1.14").
The driest months (with the least rainfall) are June, July, August and September (0.04").

Average rainfall days in September
Castroville, CA

Average rainfall days in September - Castroville, CA
  • Average rainfall days in September: 2.1 days

The month with the highest number of rainy days is March (10.2 days).
The month with the least rainy days is August (0.7 days).

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

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

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • Average sunshine in September: 11h and 1min

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

Average sunshine days in September
Castroville, CA

Average sunshine days in September - Castroville, CA
  • Average sunshine days in September: 27.3 days

The month with the most sunshine days is August (29.8 days).
The month with the least sunshine days is March (20 days).

Average UV index in September
Castroville, CA

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

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

Average cloud cover in September
Castroville, CA

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

The month with the most cloud cover is March (Cloud cover 33).
The months with the least cloud cover are July and September (Cloud cover 10).

Average visibility in September
Castroville, CA

Average visibility in September - Castroville, 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).

Castroville, California, USA

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