September weather forecast
Mill Creek, CA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Mill Creek, California, with temperature in the range of an average low of 44.6°F and an average high of 73.4°F.

Temperature

The transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a moderately hot 80.2°F in August to a still warm 73.4°F. A marked drop from daytime peak temperatures to an average low-temperature of 44.6°F is observed during the nights in September in Mill Creek.

Humidity

The average relative humidity in September in Mill Creek, California, is 47%.

Rainfall

In September, the rain falls for 5.5 days. Throughout September, 0.67" of precipitation is accumulated. Throughout the year, there are 98.1 rainfall days, and 32.99" of precipitation is accumulated.

Snowfall

Months with snowfall are January through June, September through December. September is the first month it typically snows in Mill Creek. Throughout September, in the average 0.2 snowfall days, it receives 0.47" of snow. Throughout the year, in Mill Creek, there are 66 snowfall days, and 127.72" of snow is accumulated.

Daylight

The average length of the day in September in Mill Creek is 12h and 26min.
On the first day of the month, sunrise is at 6:33 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:50 pm PDT.

Sunshine

The average sunshine in September in Mill Creek, California, is 11.1h.

UV index

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: In September, the maximum UV index of 4 transforms into these recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
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FAQ

What is the average September temperature in Mill Creek?

Mill Creek in September has an average high-temperature of 73.4°F and an average low-temperature of 44.6°F. In July, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which calculates the temperature value influenced by the moisture in the air, is evaluated at 80.6°F.

What is the average humidity in September in Mill Creek?

In September, the average relative humidity in Mill Creek, California, is 47%.

How much does it rain in Mill Creek in September?

In Mill Creek, in September, it is raining for 5.5 days, with typically 0.67" of accumulated precipitation.

When does it start to snow in Mill Creek?

September is the first month it typically snows in Mill Creek. Throughout September, in the average 0.2 snowfall days, it receives 0.47" of snow.

How many hours of daylight does Mill Creek have in September?

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

When is the sunrise / sunset in September in Mill Creek?

In September, on the first day of the month, sunrise is at 6:33 am and sunset at 7:38 pm. On the last day of the month, in Mill Creek, California, sunrise is at 7:01 am and sunset at 6:50 pm PDT.

How many hours of sunshine does Mill Creek have in September?

The average sunshine duration in September is 11.1h.

How high is the UV index in September in Mill Creek?

The average daily maximum UV index in September in Mill Creek, California, is 4. A UV Index reading of 3 to 5 represents a medium health risk from unprotected exposure to UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
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
Mill Creek, CA

Average temperature in September - Mill Creek, CA
  • Average high temperature in September: 73.4°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is December (38.3°F).

  • Average low temperature in September: 44.6°F

The month with the highest average low temperature is July (49.5°F).
The coldest month (with the lowest average low temperature) is December (24.1°F).

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Average pressure in September
Mill Creek, CA

Average pressure in September - Mill Creek, CA
  • Average pressure in September: 29.93"Hg

The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

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Average wind speed in September
Mill Creek, CA

Average wind speed in September - Mill Creek, CA
  • Average wind speed in September: 5.2mph

The windiest month (with the highest average wind speed) is March (6.7mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

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Average humidity in September
Mill Creek, CA

Average humidity in September - Mill Creek, CA
  • Average humidity in September: 47%

The month with the highest relative humidity is March (83%).
The month with the lowest relative humidity is July (42%).

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Average rainfall in September
Mill Creek, CA

Average rainfall in September - Mill Creek, CA
  • Average rainfall in September: 0.67"

The wettest month (with the highest rainfall) is March (5.59").
The driest month (with the least rainfall) is July (0.39").

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Average rainfall days in September
Mill Creek, CA

Average rainfall days in September - Mill Creek, CA
  • Average rainfall days in September: 5.5 days

The month with the highest number of rainy days is May (13.4 days).
The month with the least rainy days is August (4 days).

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Average snowfall in September
Mill Creek, CA

Average snowfall in September - Mill Creek, CA
  • Average snowfall in September: 0.47"

The month with the highest snowfall is March (27.05").
The months with the least snowfall are July and August (0").

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Average snowfall days in September
Mill Creek, CA

Average snowfall days in September - Mill Creek, CA
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is March (14 days).
The months with the least snowfall days are July and August (0 days).

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Average daylight in September /
Average sunshine in September
Mill Creek, CA

Average daylight in September / Average sunshine in September - Mill Creek, 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 24min).

  • Average sunshine in September: 11h and 1min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).

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Average sunshine days in September
Mill Creek, CA

Average sunshine days in September - Mill Creek, CA
  • Average sunshine days in September: 23.1 days

The month with the most sunshine days is August (25 days).
The month with the least sunshine days is March (10.9 days).

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Average UV index in September
Mill Creek, CA

Average UV index in September - Mill Creek, CA
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are February and November (UV index 1).

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Average cloud cover in September
Mill Creek, CA

Average cloud cover in September - Mill Creek, CA
  • Average cloud cover in September: 12

The month with the most cloud cover is March (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 7).

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Average visibility in September
Mill Creek, CA

Average visibility in September - Mill Creek, CA
  • Average visibility in September: 6mi

The months with the highest visibility are May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).

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Mill Creek, California, USA

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