Tucson
Arizona, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Tucson, AZ

Sunset in downtown Tucson, Arizona, with a skyline and a sentinel peak in the distance
Sunset in downtown Tucson, Arizona, with a skyline and a sentinel peak in the distance
September, the first month of the autumn, in Tucson, is still a hot month, with average temperature varying between 94.5°F (34.7°C) and 68.5°F (20.3°C).

Temperature

In Tucson, Arizona, the average high-temperature in September is essentially the same as in August - a hot 94.5°F (34.7°C). In Tucson, in September, the average low-temperature is 68.5°F (20.3°C).

Heat index

In September, the average heat index is evaluated at a torrid 99°F (37.2°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'felt air temperature', 'apparent temperature', or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, wind, clothing), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. When the relative humidity is high, the evaporation rate is reduced. The warmth is removed from the body at a lower rate, causing the body to retain more heat than it would in dry air. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In Tucson, the average relative humidity in September is 41.7%.

Rainfall

In Tucson, during September, the rain falls for 4.4 days and regularly aggregates up to 1.3" (32.8mm) of precipitation. Throughout the year, there are 52.9 rainfall days, and 11.6" (294.4mm) of precipitation is accumulated.

Snowfall

In Tucson, Arizona, snow does not fall in March through November.

Daylight

In Tucson, Arizona, the average length of the day is 12.4h.

Sunshine

In September, the average sunshine in Tucson, Arizona, is 10.5h.

UV index

The average daily maximum UV index in Tucson, Arizona, is 9. A UV Index value of 8 to 10 symbolizes a very high health risk from unprotected exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 9 in September transform into the following instructions:
Take extra precautions. Protection against sun damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. 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. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise.

What is the temperature in September in Tucson?

In Tucson, in September, the average high-temperature is 94.5°F (34.7°C), and the average low-temperature is 68.5°F (20.3°C). In September, the average heat index (a.k.a. 'real feel', 'felt air temperature'), that factores the actual air temperature with the relative humidity, is estimated at 99°F (37.2°C).

What is the average humidity in September in Tucson?

In Tucson, the average relative humidity in September is 41.7%.

How much does it rain in Tucson in September?

In Tucson, Arizona, in September, during 4.4 rainfall days, 1.3" (32.8mm) of precipitation is typically accumulated.

When it does not snow in Tucson?

In Tucson snow does not fall in March through November.

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

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

How long on average sun shines in September in Tucson?

In September, the average sunshine is 10.5h.

How high is the UV index in September in Tucson?

In September, the average daily maximum UV index in Tucson, Arizona, is 9. A UV Index of 8 to 10 symbolizes a very high health threat from the exposure to the Sun's UV radiation.
Average temperature in September - Tucson, AZ
  • Average high temperature in September: 94.5°F

The warmest month (with the highest average high temperature) is June (100.3°F).
The month with the lowest average high temperature is December (64.8°F).

  • Average low temperature in September: 68.6°F

The month with the highest average low temperature is July (74.4°F).
The coldest month (with the lowest average low temperature) is December (39.1°F).

Average humidity in September - Tucson, AZ
  • Average humidity in September: 41.7%

The month with the highest relative humidity is December (50%).
The month with the lowest relative humidity is June (21.1%).

Average rainfall in September - Tucson, AZ
  • Average rainfall in September: 1.3"

The wettest month (with the highest rainfall) is August (2.4").
Driest months (with the lowest rainfall) are May and June (0.2").

Average rainfall days in September - Tucson, AZ
  • Average rainfall days in September: 4.4 days

The month with the highest number of rainy days is July (9.8 days).
The month with the lowest number of rainy days is June (1.7 days).

Average snowfall in September - Tucson, AZ
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.3").
Months with the lowest snowfall are March, April, May, June, July, August, September, October and November (0").

Average snowfall days in September - Tucson, AZ
  • Average snowfall days in September: 0 days

Months with the highest number of snowfall days are January and February (0.2 days).
Months with the lowest number of snowfall days are March, April, May, June, July, August, September, October and November (0 days).

Average daylight in September / Average sunshine in September - Tucson, AZ
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.2h).
The month with shortest days is December (Average daylight: 10.1h).

  • Average sunshine in September: 10.5h

The month with most sunshine is June (Average sunshine: 13.2h).
The month with least sunshine is December (Average sunshine: 7.9h).

Average UV index in September - Tucson, AZ
  • Average UV index in September: 9

Months with the highest UV index are May, June, July and August (UV index 11).
The month with the lowest UV index is December (UV index 3).