September weather forecast
Willowbrook, CA

Share

Weather in September

The first month of the autumn, September, is still a warm month in Willowbrook, California, with an average temperature fluctuating between 80.2°F (26.8°C) and 64.8°F (18.2°C).

Temperature

At the start of September, Willowbrook's average high-temperature reaches a still warm 80.2°F (26.8°C), subtly different from the preceding month. Willowbrook sees an average low-temperature of 64.8°F (18.2°C) during September.

Humidity

In Willowbrook, the average relative humidity in September is 61%.

Rainfall

In September, in Willowbrook, the rain falls for 2.8 days. Throughout September, 0.2" (5mm) of precipitation is accumulated. Throughout the year, there are 49.7 rainfall days, and 6.77" (172mm) of precipitation is accumulated.

Daylight

In Willowbrook, the average length of the day in September is 12h and 22min.
On the first day of the month, sunrise is at 6:27 am and sunset at 7:18 pm. On the last day of September, in Willowbrook, California, sunrise is at 6:47 am and sunset at 6:38 pm PDT.

Sunshine

In Willowbrook, the average sunshine in September is 10.6h.

UV index

June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete protection. Always opt for UVA and UVB-resistant sunglasses on radiant days.
[Resources]

Frequently asked questions

What is the usual temperature for Willowbrook in September?

In Willowbrook, 80.2°F (26.8°C) is the average high-temperature and 64.8°F (18.2°C) is the average low-temperature during September. The average heat index (a.k.a. 'felt air temperature', 'feels like'), which calculates the temperature value influenced by the moisture in the air, in August is estimated at 84.2°F (29°C).

What is the average humidity in September in Willowbrook?

The average relative humidity in September in Willowbrook, California, is 61%.

How much does it rain in Willowbrook in September?

In Willowbrook, California, during September, the rain falls for 2.8 days and regularly aggregates up to 0.2" (5mm) of precipitation.

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

In September, the average day length in Willowbrook, California, is 12h and 22min.

What time are sunrise and sunset in September in Willowbrook?

On the first day of September in Willowbrook, California, sunrise is at 6:27 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:38 pm PDT.

How many hours of sunshine does Willowbrook have in September?

In September, the average sunshine duration is 10.6h.

What is the month with the highest UV index in Willowbrook?

June through September, with an average maximum UV index of 6, are months with the highest UV index.

What is the UV index reading in September in Willowbrook?

The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Willowbrook, CA

Average temperature in September - Willowbrook, CA
  • Average high temperature in September: 80.2°F

The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (64°F).

  • Average low temperature in September: 64.8°F

The month with the highest average low temperature is August (65.1°F).
The coldest month (with the lowest average low temperature) is February (51.4°F).

[Resources]

Average pressure in September
Willowbrook, CA

Average pressure in September - Willowbrook, CA
  • Average pressure in September: 29.89"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.89"Hg).

[Resources]

Average wind speed in September
Willowbrook, CA

Average wind speed in September - Willowbrook, CA
  • Average wind speed in September: 4.8mph

The windiest month (with the highest average wind speed) is April (6.3mph).
The calmest months (with the lowest average wind speed) are September and October (4.8mph).

[Resources]

Average humidity in September
Willowbrook, CA

Average humidity in September - Willowbrook, CA
  • Average humidity in September: 61%

The month with the highest relative humidity is June (69%).
The month with the lowest relative humidity is November (53%).

[Resources]

Average rainfall in September
Willowbrook, CA

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

The wettest months (with the highest rainfall) are January and February (1.26").
The driest month (with the least rainfall) is June (0.08").

[Resources]

Average rainfall days in September
Willowbrook, CA

Average rainfall days in September - Willowbrook, CA
  • Average rainfall days in September: 2.8 days

The month with the highest number of rainy days is March (7 days).
The month with the least rainy days is June (1.3 days).

[Resources]

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

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

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in September: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).

[Resources]

Average sunshine days in September
Willowbrook, CA

Average sunshine days in September - Willowbrook, CA
  • Average sunshine days in September: 23.2 days

The month with the most sunshine days is August (25.3 days).
The month with the least sunshine days is February (21.1 days).

[Resources]

Average UV index in September
Willowbrook, CA

Average UV index in September - Willowbrook, CA
  • Average UV index in September: 6

The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).

[Resources]

Average cloud cover in September
Willowbrook, CA

Average cloud cover in September - Willowbrook, CA
  • Average cloud cover in September: 10

The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 6).

[Resources]

Average visibility in September
Willowbrook, CA

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

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

[Resources]

Willowbrook, California, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location