September weather forecast
Thornton, CA

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Weather in September

September, the first month of the autumn in Thornton, is still a tropical month, with an average temperature fluctuating between 88.5°F (31.4°C) and 58.6°F (14.8°C).

Temperature

Thornton ushers in September with an average high-temperature of a still tropical 88.5°F (31.4°C), showing a close resemblance to the previous month. Despite a significant daily temperature range, Thornton's temperature falls to a steady low-temperature average of 58.6°F (14.8°C) in September.

Heat index

The heat index in September is estimated at a tropical 89.6°F (32°C). Long-standing exposure and activity could induce a feeling of tiredness and lead to heat cramps.
Heat index readings emphasize conditions of light breezes and shaded spots. Direct sunlight has the potential to heighten heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a single figure representing how weather conditions feel when combining temperature and humidity. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. When you're directly under the sun's rays, remember that the heat index may surge by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Children often fail to understand the importance of rest and rehydration. Thirst is a late manifestation of dehydration - hence, it is crucial to stay hydrated, especially during ongoing physical activities.

Humidity

The average relative humidity in September in Thornton is 46%.

Rainfall

In September, the rain falls for 1.5 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Thornton, during the entire year, the rain falls for 63.8 days and collects up to 12.6" (320mm) of precipitation.

Snowfall

January through November are months without snowfall.

Daylight

The average length of the day in September in Thornton is 12h and 25min.
On the first day of the month, sunrise is at 6:36 am and sunset at 7:34 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:49 pm PDT.

Sunshine

The average sunshine in September in Thornton is 11.3h.

UV index

The average daily maximum UV index in September in Thornton, California, is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum UV index of 5 in September translates into the following recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
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Frequently asked questions

How hot is it in Thornton in September?

In September, the average high-temperature and low-temperature in Thornton, California, are 88.5°F (31.4°C) and 58.6°F (14.8°C) respectively. The average heat index (a.k.a. 'real feel', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in September is estimated at 89.6°F (32°C).

What is the average humidity in September in Thornton?

In September, the average relative humidity is 46%.

How many days does it rain in September in Thornton?

In Thornton, California, during September, the rain falls for 1.5 days and regularly aggregates up to 0.08" (2mm) of precipitation.

When it does not snow in Thornton?

In Thornton, snow does not fall in January through November.

How many hours of daylight does Thornton have in September?

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

When are sunrise and sunset in September in Thornton?

In September, on the first day of the month, sunrise is at 6:36 am and sunset at 7:34 pm. On the last day of the month, in Thornton, sunrise is at 7:01 am and sunset at 6:49 pm PDT.

How many hours of sunshine does Thornton have in September?

In Thornton, California, the average sunshine duration in September is 11.3h.

What is the UV index intensity in September in Thornton?

In Thornton, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Thornton, CA

Average temperature in September - Thornton, CA
  • Average high temperature in September: 88.5°F

The warmest month (with the highest average high temperature) is July (93.9°F).
The month with the lowest average high temperature is December (55°F).

  • Average low temperature in September: 58.6°F

The month with the highest average low temperature is August (58.8°F).
The coldest month (with the lowest average low temperature) is December (41°F).

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Average pressure in September
Thornton, CA

Average pressure in September - Thornton, CA
  • Average pressure in September: 29.92"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

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Average wind speed in September
Thornton, CA

Average wind speed in September - Thornton, CA
  • Average wind speed in September: 4.6mph

The windiest months (with the highest average wind speed) are February and June (5.8mph).
The calmest month (with the lowest average wind speed) is November (4.4mph).

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Average humidity in September
Thornton, CA

Average humidity in September - Thornton, CA
  • Average humidity in September: 46%

The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is July (45%).

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Average rainfall in September
Thornton, CA

Average rainfall in September - Thornton, CA
  • Average rainfall in September: 0.08"

The wettest month (with the highest rainfall) is February (2.4").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Thornton, CA

Average rainfall days in September - Thornton, CA
  • Average rainfall days in September: 1.5 days

The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is June (0.9 days).

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Average snowfall days in September
Thornton, CA

Average snowfall days in September - Thornton, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).

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

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

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 11h and 2min

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).

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Average sunshine days in September
Thornton, CA

Average sunshine days in September - Thornton, CA
  • Average sunshine days in September: 27.5 days

The month with the most sunshine days is August (29.3 days).
The month with the least sunshine days is March (17.8 days).

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Average UV index in September
Thornton, CA

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

The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in September
Thornton, CA

Average cloud cover in September - Thornton, CA
  • Average cloud cover in September: 7

The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 4).

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Average visibility in September
Thornton, CA

Average visibility in September - Thornton, 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).

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Thornton, California, USA

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