September weather forecast
East Palo Alto, CA

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Weather in September

The first month of the autumn, September, is still a warm month in East Palo Alto, California, with an average temperature fluctuating between 76.5°F (24.7°C) and 56.7°F (13.7°C).

Temperature

The beginning of September records an average high-temperature of a still moderately hot 76.5°F (24.7°C), almost echoing the conditions of the previous month. East Palo Alto experiences an average low-temperature of 56.7°F (13.7°C) in the month of September.

Humidity

September and October, with an average relative humidity of 65%, are the least humid months.

Rainfall

In East Palo Alto, in September, it is raining for 2.1 days, with typically 0.08" (2mm) of accumulated precipitation. In East Palo Alto, during the entire year, the rain falls for 63.3 days and collects up to 9.53" (242mm) of precipitation.

Daylight

The average length of the day in September is 12h and 25min.
On the first day of the month, sunrise is at 6:39 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:52 pm PDT.

Sunshine

In East Palo Alto, the average sunshine in September is 11h.

UV index

The months with the highest UV index are April through October, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: A daily maximum UV index of 5 in September translates into the following instructions:
Ensure safety - Sun damage prevention is strongly urged. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in East Palo Alto in September?

In September, in East Palo Alto, the average high-temperature is 76.5°F (24.7°C), and the average low-temperature is 56.7°F (13.7°C).

What is the least humid month in East Palo Alto?

The months with the lowest humidity in East Palo Alto are September and October, with an average relative humidity of 65%.

What is the average humidity in September in East Palo Alto?

In East Palo Alto, California, the average relative humidity in September is 65%.

How many days does it rain in September in East Palo Alto?

In September, in East Palo Alto, California, the rain falls for 2.1 days. Throughout September, 0.08" (2mm) of precipitation is accumulated.

What is the average length of the day in September in East Palo Alto?

In East Palo Alto, California, the average day length in September is 12h and 25min.

When is the sunrise / sunset in September in East Palo Alto?

In September, on the first day of the month, sunrise is at 6:39 am and sunset at 7:36 pm. On the last day of the month, in East Palo Alto, California, sunrise is at 7:03 am and sunset at 6:52 pm PDT.

How many hours of sunshine does East Palo Alto have in September?

In East Palo Alto, California, the average sunshine duration in September is 11h.

What are the months with the highest UV index in East Palo Alto?

The months with the highest UV index in East Palo Alto are April through October, with an average maximum UV index of 5.

What is the UV index reading in September in East Palo Alto?

In September, the average daily maximum UV index in East Palo Alto is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
East Palo Alto, CA

Average temperature in September - East Palo Alto, CA
  • Average high temperature in September: 76.5°F

The warmest months (with the highest average high temperature) are July and August (77.5°F).
The month with the lowest average high temperature is December (56.3°F).

  • Average low temperature in September: 56.7°F

The month with the highest average low temperature is August (57°F).
The coldest months (with the lowest average low temperature) are January and February (45.1°F).

Average pressure in September
East Palo Alto, CA

Average pressure in September - East Palo Alto, 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 and September (29.92"Hg).

Average wind speed in September
East Palo Alto, CA

Average wind speed in September - East Palo Alto, CA
  • Average wind speed in September: 4.9mph

The windiest months (with the highest average wind speed) are April and May (6.5mph).
The calmest months (with the lowest average wind speed) are September and October (4.9mph).

Average humidity in September
East Palo Alto, CA

Average humidity in September - East Palo Alto, CA
  • Average humidity in September: 65%

The month with the highest relative humidity is March (74%).
The months with the lowest relative humidity are September and October (65%).

Average rainfall in September
East Palo Alto, CA

Average rainfall in September - East Palo Alto, CA
  • Average rainfall in September: 0.08"

The wettest month (with the highest rainfall) is February (2.01").
The driest month (with the least rainfall) is July (0").

Average rainfall days in September
East Palo Alto, CA

Average rainfall days in September - East Palo Alto, CA
  • Average rainfall days in September: 2.1 days

The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (0.6 days).

Average daylight in September /
Average sunshine in September
East Palo Alto, CA

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

The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 11h and 0min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).

Average sunshine days in September
East Palo Alto, CA

Average sunshine days in September - East Palo Alto, CA
  • Average sunshine days in September: 27.6 days

The month with the most sunshine days is July (30.2 days).
The month with the least sunshine days is March (18 days).

Average UV index in September
East Palo Alto, CA

Average UV index in September - East Palo Alto, CA
  • Average UV index in September: 5

The months with the highest UV index are April, May, June, July, August, September and October (UV index 5).
The months with the lowest UV index are February, November and December (UV index 3).

Average cloud cover in September
East Palo Alto, CA

Average cloud cover in September - East Palo Alto, CA
  • Average cloud cover in September: 11

The months with the most cloud cover are March and December (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 6).

Average visibility in September
East Palo Alto, CA

Average visibility in September - East Palo Alto, 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).

East Palo Alto, California, USA

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