September weather forecast and climate
Tustin, CA

Weather in September

September, the first month of the autumn, in Tustin, is also a moderately hot month, with average temperature fluctuating between 64.4°F (18°C) and 79.7°F (26.5°C).

Temperature

In Tustin, the average high-temperature in September is practically the same as in August - a still warm 79.7°F (26.5°C). In September, in Tustin, the average low-temperature is 64.4°F (18°C).

Humidity

In September, the average relative humidity is 63%.

Rainfall

In September, in Tustin, the rain falls for 3.1 days. Throughout September, 0.16" (4mm) of precipitation is accumulated. In Tustin, during the entire year, the rain falls for 51.9 days and collects up to 4.13" (105mm) of precipitation.

Daylight

The average length of the day in Tustin is 12.4h.

Sunshine

The average sunshine in Tustin is 10.6h.

UV index

Months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health hazard from unprotected exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 6 in September transform into the following instructions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the temperature in September in Tustin?

In September, in Tustin, the average high-temperature is 79.7°F (26.5°C), and the average low-temperature is 64.4°F (18°C).

What is the average humidity in September in Tustin?

In Tustin, California, the average relative humidity in September is 63%.

How many days does it rain in September in Tustin?

In September, in Tustin, the rain falls for 3.1 days. Throughout September, 0.16" (4mm) of precipitation is accumulated.

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

The average length of the day in September in Tustin, California, is 12.4h.

How many hours of sunshine does Tustin have in September?

In September, the average sunshine in Tustin, California, is 10.6h.

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

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

What is the UV index intensity in September in Tustin?

In September, the average daily maximum UV index in Tustin, California, is 6. A UV Index of 6 to 7 symbolizes a high hazard to health from the exposure to the Sun's UV rays.

Average temperature in September
Tustin, CA

Average temperature in September - Tustin, CA
  • Average high temperature in September: 79.7°F

The warmest month (with the highest average high temperature) is August (80.2°F).
The month with the lowest average high temperature is December (63.1°F).

  • Average low temperature in September: 64.4°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 (50.7°F).

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Average pressure in September
Tustin, CA

Average pressure in September - Tustin, CA
  • Average pressure in September: 29.89"

The month with the highest atmospheric pressure is January (30.1").
The month with the lowest atmospheric pressure is June (29.88").

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Average wind speed in September
Tustin, CA

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

The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest months (with the lowest average wind speed) are August, September and October (4.8mph).

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Average humidity in September
Tustin, CA

Average humidity in September - Tustin, CA
  • Average humidity in September: 63%

The month with the highest relative humidity is June (70%).
The month with the lowest relative humidity is November (55%).

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Average rainfall in September
Tustin, CA

Average rainfall in September - Tustin, CA
  • Average rainfall in September: 0.16"

The wettest month (with the highest rainfall) is December (0.87").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Tustin, CA

Average rainfall days in September - Tustin, CA
  • Average rainfall days in September: 3.1 days

The month with the highest number of rainy days is March (6.7 days).
The month with the least rainy days is June (1.3 days).

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

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

The month with the longest days is June (Average daylight: 14.4h).
The month with the shortest days is December (Average daylight: 9.9h).

  • Average sunshine in September: 10.6h

Months with the most sunshine are July and August (Average sunshine: 12h).
The month with the least sunshine is December (Average sunshine: 6.7h).

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Average sunshine days in September
Tustin, CA

Average sunshine days in September - Tustin, CA
  • Average sunshine days in September: 24.1 days

The month with the most sunshine days is June (26.9 days).
The month with the least sunshine days is February (20.3 days).

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Average UV index in September
Tustin, CA

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

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

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Average cloud cover in September
Tustin, CA

Average cloud cover in September - Tustin, CA
  • Average cloud cover in September: 9

Months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 6).

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Average visibility in September
Tustin, CA

Average visibility in September - Tustin, 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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