September weather forecast
Rio Dell, CA

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Weather in September

The first month of the autumn, September, is still a pleasant month in Rio Dell, California, with an average temperature ranging between max 72.5°F (22.5°C) and min 50.9°F (10.5°C).

Temperature

September's weather displays an average high-temperature of an agreeable 72.5°F (22.5°C), slightly varied from August's 74.1°F (23.4°C). Rio Dell reports a marked divergence from daytime peaks throughout September, with lows averaging at a fresh 50.9°F (10.5°C).

Humidity

The least humid month is September, with an average relative humidity of 73%.

Rainfall

In Rio Dell, during September, the rain falls for 4 days and regularly aggregates up to 0.59" (15mm) of precipitation. In Rio Dell, California, during the entire year, the rain falls for 110.9 days and collects up to 28.27" (718mm) of precipitation.

Snowfall

January, March through December are months without snowfall.

Daylight

In September, the average length of the day is 12h and 26min.
On the first day of September, sunrise is at 6:44 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:59 pm PDT.

Sunshine

The average sunshine in September is 10.2h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 4 in September transforms into the following instructions:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Updated: Aug 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

September temperatures vary between a high-temperature of 72.5°F (22.5°C) and a low-temperature of 50.9°F (10.5°C).

What is the least humid month?

The least humid month is September, with an average relative humidity of 73%.

What is the average humidity in September?

The average relative humidity in September in Rio Dell, California, is 73%.

How much does it rain in September?

In Rio Dell, in September, during 4 rainfall days, 0.59" (15mm) of precipitation is typically accumulated.

When it does not snow?

January, March through December are months without snowfall.

What is the average length of the day in September?

In September, the average day length is 12h and 26min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:44 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:59 pm PDT.

How long on average sun shines in September?

In Rio Dell, the average sunshine duration in September is 10.2h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium hazard to health from exposure to the Sun's 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
Rio Dell, CA

Average temperature in September - Rio Dell, CA
  • Average high temperature in September: 72.5°F

The warmest month (with the highest average high temperature) is August (74.1°F).
The month with the lowest average high temperature is December (52.9°F).

  • Average low temperature in September: 50.9°F

The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is February (39.7°F).

Average pressure in September
Rio Dell, CA

Average pressure in September - Rio Dell, CA
  • Average pressure in September: 29.96"Hg

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

Average wind speed in September
Rio Dell, CA

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

The windiest month (with the highest average wind speed) is June (7.7mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).

Average humidity in September
Rio Dell, CA

Average humidity in September - Rio Dell, CA
  • Average humidity in September: 73%

The month with the highest relative humidity is March (83%).
The month with the lowest relative humidity is September (73%).

Average rainfall in September
Rio Dell, CA

Average rainfall in September - Rio Dell, CA
  • Average rainfall in September: 0.59"

The wettest month (with the highest rainfall) is December (4.96").
The driest month (with the least rainfall) is July (0.08").

Average rainfall days in September
Rio Dell, CA

Average rainfall days in September - Rio Dell, CA
  • Average rainfall days in September: 4 days

The month with the highest number of rainy days is March (17.3 days).
The months with the least rainy days are July and August (1.8 days).

Average snowfall in September
Rio Dell, CA

Average snowfall in September - Rio Dell, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.59").
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
Rio Dell, CA

Average snowfall days in September - Rio Dell, 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
Rio Dell, CA

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

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 10h and 1min

The months with the most sunshine are July and August (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).

Average sunshine days in September
Rio Dell, CA

Average sunshine days in September - Rio Dell, CA
  • Average sunshine days in September: 25.8 days

The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (11.9 days).

Average UV index in September
Rio Dell, CA

Average UV index in September - Rio Dell, CA
  • Average UV index in September: 4

The months with the highest UV index are June, July and August (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
Rio Dell, CA

Average cloud cover in September - Rio Dell, CA
  • Average cloud cover in September: 19

The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 16).

Average visibility in September
Rio Dell, CA

Average visibility in September - Rio Dell, CA
  • Average visibility in September: 6mi

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

Rio Dell, California, USA

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