September weather forecast
Ukiah, CA

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Weather in September

The first month of the autumn, September, is still a warm month in Ukiah, California, with temperature in the range of an average low of 51.4°F (10.8°C) and an average high of 80.8°F (27.1°C).

Temperature

Ukiah experiences a minor change to a still warm 80.8°F (27.1°C) in average high-temperature during September, closely reflecting August. Ukiah documents a substantial shift from daytime warmth, recording an average nighttime temperature of 51.4°F (10.8°C) in September.

Heat index

In September, the heat index is calculated to be 82.4°F (28°C). Persisting in activity during exposure could lead to weariness and subsequently to heat cramps.
Research indicates the heat index considers values in shaded locales and with light winds. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', gives a temperature feeling by integrating air temperature and humidity. The influence of weather is personal, with varied individuals experiencing it differently due to differences in body mass, stature, and physical exertion levels. Do note, being directly under sun rays can amplify the heat you feel, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.

Humidity

The months with the lowest humidity in Ukiah are July and September, with an average relative humidity of 58%.

Rainfall

In Ukiah, in September, it is raining for 2.5 days, with typically 0.2" (5mm) of accumulated precipitation. In Ukiah, during the entire year, the rain falls for 83.3 days and collects up to 17.72" (450mm) 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 the month, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:56 pm PDT.

Sunshine

In September, the average sunshine is 10.9h.

UV index

In Ukiah, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.
Note: In September, the maximum UV index of 4 suggests these recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
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Frequently asked questions

What is the usual temperature for Ukiah in September?

The average high-temperature, in September, in Ukiah, is 80.8°F (27.1°C), while the average low-temperature is 51.4°F (10.8°C). In September, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, is calculated to be 82.4°F (28°C).

What are the least humid months in Ukiah?

July and September, with an average relative humidity of 58%, are the least humid months.

What is the average humidity in September in Ukiah?

In Ukiah, California, the average relative humidity in September is 58%.

How many days does it rain in September in Ukiah?

In Ukiah, California, in September, during 2.5 rainfall days, 0.2" (5mm) of precipitation is typically accumulated.

When it does not snow in Ukiah?

January, March through December are months without snowfall in Ukiah.

How many hours of daylight does Ukiah have in September?

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

When are sunrise and sunset in September in Ukiah?

In September, on the first day of the month, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, in Ukiah, California, sunrise is at 7:08 am and sunset at 6:56 pm PDT.

How many hours of sunshine does Ukiah have in September?

In September, the average sunshine duration in Ukiah is 10.9h.

How high is the UV index in September in Ukiah?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health threat from exposure to Sun's UV rays.
Average max. wind speed
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
Ukiah, CA

Average temperature in September - Ukiah, CA
  • Average high temperature in September: 80.8°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (53.6°F).

  • Average low temperature in September: 51.4°F

The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is December (37.4°F).

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Average pressure in September
Ukiah, CA

Average pressure in September - Ukiah, 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).

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Average wind speed in September
Ukiah, CA

Average wind speed in September - Ukiah, CA
  • Average wind speed in September: 4.4mph

The windiest months (with the highest average wind speed) are April, May and June (5.5mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).

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Average humidity in September
Ukiah, CA

Average humidity in September - Ukiah, CA
  • Average humidity in September: 58%

The month with the highest relative humidity is March (79%).
The months with the lowest relative humidity are July and September (58%).

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Average rainfall in September
Ukiah, CA

Average rainfall in September - Ukiah, CA
  • Average rainfall in September: 0.2"

The wettest months (with the highest rainfall) are February and December (3.11").
The driest months (with the least rainfall) are July and August (0.08").

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Average rainfall days in September
Ukiah, CA

Average rainfall days in September - Ukiah, CA
  • Average rainfall days in September: 2.5 days

The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is August (1.3 days).

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Average snowfall in September
Ukiah, CA

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

The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

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Average snowfall days in September
Ukiah, CA

Average snowfall days in September - Ukiah, 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, November and December (0 days).

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

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

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 10h and 5min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).

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Average sunshine days in September
Ukiah, CA

Average sunshine days in September - Ukiah, CA
  • Average sunshine days in September: 26.9 days

The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (15.9 days).

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Average UV index in September
Ukiah, CA

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

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are February and November (UV index 2).

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Average cloud cover in September
Ukiah, CA

Average cloud cover in September - Ukiah, CA
  • Average cloud cover in September: 11

The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).

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Average visibility in September
Ukiah, CA

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

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

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Ukiah, California, USA

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