September weather forecast
Arcata, CA

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Weather in September

The first month of the autumn, September, is also an agreeable month in Arcata, California, with an average temperature varying between 51.6°F (10.9°C) and 68.9°F (20.5°C).

Temperature

Arcata's shift into September sets the average high-temperature at a still agreeable 68.9°F (20.5°C), a figure that deviates only slightly from August's 69.6°F (20.9°C). Arcata records a steady low-temperature average of 51.6°F (10.9°C) during September.

Humidity

In Arcata, California, the average relative humidity in September is 76%.

Rainfall

In Arcata, California, in September, during 4.5 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. Throughout the year, there are 114.7 rainfall days, and 29.37" (746mm) of precipitation is accumulated.

Snowfall

In Arcata, California, snow does not fall in January, March through December.

Daylight

In Arcata, the average length of the day in September is 12h and 27min.
On the first day of the month, sunrise is at 6:44 am and sunset at 7:48 pm. On the last day of September, in Arcata, sunrise is at 7:12 am and sunset at 6:59 pm PDT.

Sunshine

In September, the average sunshine in Arcata is 10.3h.

UV index

In Arcata, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A daily high UV index of 4 in September leads to these guidelines:
Put precautions into practice - Protective measures against sun-induced damage are advised. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.

Frequently asked questions

What are the temperatures in Arcata in September?

In Arcata, in September, the average high-temperature is 68.9°F (20.5°C), and the average low-temperature is 51.6°F (10.9°C).

What is the average humidity in September in Arcata?

In September, the average relative humidity is 76%.

How many days does it rain in September in Arcata?

In Arcata, California, in September, it is raining for 4.5 days, with typically 0.79" (20mm) of accumulated precipitation.

When it does not snow in Arcata?

January, March through December are months without snowfall.

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

In September, the average day length in Arcata is 12h and 27min.

What time are sunrise and sunset in September in Arcata?

On the first day of September in Arcata, California, sunrise is at 6:44 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:59 pm PDT.

How many hours of sunshine does Arcata have in September?

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

What is the UV index intensity in September in Arcata?

In September, the average daily maximum UV index in Arcata is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Arcata, CA

Average temperature in September - Arcata, CA
  • Average high temperature in September: 68.9°F

The warmest month (with the highest average high temperature) is August (69.6°F).
The month with the lowest average high temperature is December (52.7°F).

  • Average low temperature in September: 51.6°F

The month with the highest average low temperature is August (52.3°F).
The coldest month (with the lowest average low temperature) is February (41.9°F).

Average pressure in September
Arcata, CA

Average pressure in September - Arcata, CA
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is August (29.96"Hg).

Average wind speed in September
Arcata, CA

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

The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).

Average humidity in September
Arcata, CA

Average humidity in September - Arcata, CA
  • Average humidity in September: 76%

The month with the highest relative humidity is March (82%).
The month with the lowest relative humidity is October (75%).

Average rainfall in September
Arcata, CA

Average rainfall in September - Arcata, CA
  • Average rainfall in September: 0.79"

The wettest month (with the highest rainfall) is December (5.31").
The driest month (with the least rainfall) is July (0.12").

Average rainfall days in September
Arcata, CA

Average rainfall days in September - Arcata, CA
  • Average rainfall days in September: 4.5 days

The month with the highest number of rainy days is March (17.5 days).
The month with the least rainy days is August (2.1 days).

Average snowfall in September
Arcata, CA

Average snowfall in September - Arcata, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.39").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in September
Arcata, CA

Average snowfall days in September - Arcata, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (0.3 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October and November (0 days).

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

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

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 10h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 12min).

Average sunshine days in September
Arcata, CA

Average sunshine days in September - Arcata, CA
  • Average sunshine days in September: 24.9 days

The month with the most sunshine days is July (28.3 days).
The month with the least sunshine days is March (12.1 days).

Average UV index in September
Arcata, CA

Average UV index in September - Arcata, CA
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 3).

Average cloud cover in September
Arcata, CA

Average cloud cover in September - Arcata, CA
  • Average cloud cover in September: 18

The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 16).

Average visibility in September
Arcata, CA

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

The months with the highest visibility are January, February, March, April, May, June, July, September, October, November and December (6mi).
The month with the lowest visibility is August (5mi).

Arcata, California, USA

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