September weather forecast
Ukiah, CA

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Weather in September

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

Temperature

The advent of September observes an average high-temperature of a still warm 80.8°F (27.1°C), nearly identical to August's 84.7°F (29.3°C). Ukiah reports a sharp reduction in temperature during September, averaging at a fresh 51.4°F (10.8°C) at night.

Heat index

In September, the heat index is computed to be 82.4°F (28°C). If one remains active during constant exposure, it might cause exhaustion and heat cramps.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. The heat index has the possibility to be enhanced by 15 Fahrenheit (8 Celsius) degrees when there is direct sun exposure.
Note: The heat index, also known as 'real feel' or 'feels like', is a metric representing the sensation of warmth when air temperature and moisture come together. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. Given the impact of direct sunlight, it's noteworthy that the felt temperature can rise by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Kids are usually in more danger than grown-ups as they tend to sweat less. Plus, their bigger skin surface in relation to their small frames and increased heat generation due to their activity level make them more susceptible.

Humidity

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

Rainfall

In Ukiah, during September, the rain falls for 2.5 days and regularly aggregates up to 0.2" (5mm) of precipitation. Throughout the year, in Ukiah, there are 83.3 rainfall days, and 17.72" (450mm) of precipitation is accumulated.

Snowfall

January, March through December are months without snowfall.

Daylight

In Ukiah, the average length of the day in September 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

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In September, the maximum UV index of 4 translates into these guidelines:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Updated: Jun 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The high-temperature, in September, in Ukiah, records 80.8°F (27.1°C), while the low-temperature is 51.4°F (10.8°C). In September, the average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 82.4°F (28°C).

What are the least humid months?

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

What is the average humidity in September in Ukiah?

The average relative humidity in September is 58%.

How many days does it rain in September?

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

When it does not snow?

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

What is the average length of the day in September?

The average day length in September is 12h and 26min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, 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.

What is the UV index intensity in September in Ukiah?

In Ukiah, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health from unprotected exposure to UV radiation.
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).

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).

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).

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%).

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").

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).

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").

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).

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).

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).

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).

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).

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).

Ukiah, California, USA

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