September weather forecast and climate
Lafayette, CA

Weather in September

The first month of the autumn, September, is also a moderately hot month in Lafayette, California, with average temperature ranging between max 79.5°F (26.4°C) and min 56.8°F (13.8°C).

Temperature

In Lafayette, the average high-temperature is practically the same as in August - a still warm 79.5°F (26.4°C). In Lafayette, the average low-temperature is 56.8°F (13.8°C).

Humidity

The average relative humidity in September is 61%.

Rainfall

In Lafayette, during September, the rain falls for 2.8 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, there are 74.4 rainfall days, and 12.6" (320mm) of precipitation is accumulated.

Daylight

In September, the average length of the day in Lafayette is 12.4h.

Sunshine

In Lafayette, the average sunshine in September is 11.1h.

UV index

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The average daily UV index of 5 transform into the following instructions:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the temperature in September in Lafayette?

The average high-temperature, in September, in Lafayette, is 79.5°F (26.4°C), while the average low-temperature is 56.8°F (13.8°C).

What is the average humidity in September in Lafayette?

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

How much does it rain in Lafayette in September?

In September, in Lafayette, California, the rain falls for 2.8 days. Throughout September, 0.12" (3mm) of precipitation is accumulated.

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

In September, the average length of the day is 12.4h.

How many hours of sunshine does Lafayette have in September?

The average sunshine in September in Lafayette is 11.1h.

What is the UV index reading in September in Lafayette?

In Lafayette, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from the exposure to the Sun's UV rays.

Average temperature in September
Lafayette, CA

Average temperature in September - Lafayette, CA
  • Average high temperature in September: 79.5°F

The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is December (55.2°F).

  • Average low temperature in September: 56.8°F

Months with the highest average low temperature are August and September (56.8°F).
The coldest month (with the lowest average low temperature) is January (43.3°F).

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Average pressure in September
Lafayette, CA

Average pressure in September - Lafayette, CA
  • Average pressure in September: 29.92"

The month with the highest atmospheric pressure is January (30.14").
Months with the lowest atmospheric pressure are June, August and September (29.92").

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Average wind speed in September
Lafayette, CA

Average wind speed in September - Lafayette, CA
  • Average wind speed in September: 5.5mph

The windiest month (with the highest average wind speed) is May (7.2mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).

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Average humidity in September
Lafayette, CA

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

The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is October (60%).

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Average rainfall in September
Lafayette, CA

Average rainfall in September - Lafayette, CA
  • Average rainfall in September: 0.12"

The wettest month (with the highest rainfall) is February (2.6").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Lafayette, CA

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

The month with the highest number of rainy days is March (13.1 days).
The month with the least rainy days is August (0.8 days).

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

Average daylight in September / Average sunshine in September - Lafayette, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in September: 11.1h

The month with the most sunshine is July (Average sunshine: 12h).
The month with the least sunshine is December (Average sunshine: 5.8h).

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Average sunshine days in September
Lafayette, CA

Average sunshine days in September - Lafayette, CA
  • Average sunshine days in September: 25.9 days

The month with the most sunshine days is August (27.8 days).
The month with the least sunshine days is March (16.3 days).

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Average UV index in September
Lafayette, CA

Average UV index in September - Lafayette, CA
  • Average UV index in September: 5

The month with the highest UV index is June (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in September
Lafayette, CA

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

The month with the most cloud cover is March (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 8).

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Average visibility in September
Lafayette, CA

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

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

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