September weather forecast
Upland, CA

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Weather in September

September, the first month of the autumn in Upland, is still a hot month, with an average temperature varying between 63.5°F (17.5°C) and 88.2°F (31.2°C).

Temperature

The advent of September presents an average high-temperature of a still hot 88.2°F (31.2°C), maintaining a close correlation with the preceding month. A noteworthy thermal contrast characterizes Upland's September nights, with temperatures averaging at a refreshing 63.5°F (17.5°C).

Heat index

September's heat index is computed to be a hot 89.6°F (32°C). Prolonged exposure combined with continuous activity could lead to exhaustion, and possibly heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'feels like' or 'real feel', comes about by integrating the temperature readings with the humidity levels. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Youngsters are usually more at risk than adults, considering they sweat less. Additionally, their high skin surface area compared to their little bodies and their high heat production due to activity increases their risk.

Humidity

In Upland, California, the average relative humidity in September is 44%.

Rainfall

In September, the rain falls for 2.5 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. In Upland, during the entire year, the rain falls for 49.6 days and collects up to 7.8" (198mm) of precipitation.

Snowfall

January, March through December are months without snowfall in Upland, California.

Daylight

The average length of the day in September in Upland is 12h and 22min.
On the first day of September, sunrise is at 6:24 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:35 pm PDT.

Sunshine

In Upland, the average sunshine in September is 10.7h.

UV index

The average daily maximum UV index in September in Upland is 6. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for average individuals.
Note: The average daily UV index of 6 in September transforms into the following instructions:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
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Frequently asked questions

Is it hot in Upland during September?

During September, Upland experiences an average high-temperature of 88.2°F (31.2°C) and a low-temperature of 63.5°F (17.5°C). In September, the average heat index (a.k.a. 'feels like', 'real feel'), which combines relative humidity and air temperature, is computed to be 89.6°F (32°C).

What is the average humidity in September in Upland?

The average relative humidity in September in Upland, California, is 44%.

How many days does it rain in September in Upland?

In September, in Upland, California, the rain falls for 2.5 days. Throughout September, 0.12" (3mm) of precipitation is accumulated.

When it does not snow in Upland?

In Upland, California, snow does not fall in January, March through December.

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

The average day length in September in Upland is 12h and 22min.

What time are sunrise and sunset in September in Upland?

On the first day of September in Upland, sunrise is at 6:24 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:35 pm PDT.

How many hours of sunshine does Upland have in September?

In September, the average sunshine duration in Upland is 10.7h.

What is the UV index intensity in September in Upland?

In September, the average daily maximum UV index in Upland, California, is 6. A UV Index of 6 to 7 symbolizes a high hazard to health 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
Upland, CA

Average temperature in September - Upland, CA
  • Average high temperature in September: 88.2°F

The warmest month (with the highest average high temperature) is August (91°F).
The month with the lowest average high temperature is December (62.1°F).

  • Average low temperature in September: 63.5°F

The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).

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Average pressure in September
Upland, CA

Average pressure in September - Upland, CA
  • Average pressure in September: 29.88"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).

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Average wind speed in September
Upland, CA

Average wind speed in September - Upland, CA
  • Average wind speed in September: 4.4mph

The windiest months (with the highest average wind speed) are April and May (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).

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Average humidity in September
Upland, CA

Average humidity in September - Upland, CA
  • Average humidity in September: 44%

The months with the highest relative humidity are March and May (54%).
The month with the lowest relative humidity is August (42%).

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Average rainfall in September
Upland, CA

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

The wettest month (with the highest rainfall) is February (1.77").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in September
Upland, CA

Average rainfall days in September - Upland, CA
  • Average rainfall days in September: 2.5 days

The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (1.2 days).

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Average snowfall days in September
Upland, CA

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

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

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

Average daylight in September / Average sunshine in September - Upland, 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 month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).

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Average sunshine days in September
Upland, CA

Average sunshine days in September - Upland, CA
  • Average sunshine days in September: 25.4 days

The month with the most sunshine days is June (28.2 days).
The month with the least sunshine days is February (21.5 days).

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Average UV index in September
Upland, CA

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

The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).

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Average cloud cover in September
Upland, CA

Average cloud cover in September - Upland, CA
  • Average cloud cover in September: 6

The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).

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Average visibility in September
Upland, CA

Average visibility in September - Upland, 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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Upland, California, USA

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