September weather forecast
Donaldsonville, LA

Share

Weather in September

September, the first month of the autumn in Donaldsonville, is also a hot month, with an average temperature varying between 87.3°F (30.7°C) and 70.5°F (21.4°C).

Temperature

September's climate shows a minor adjustment in average high-temperatures to a still hot 87.3°F (30.7°C) from August's 90.1°F (32.3°C). During the nights in September, the temperature averages to an agreeable 70.5°F (21.4°C).

Heat index

The heat index value for September is appraised at a scorching 104°F (40°C). Adopt extra preventive measures, the occurrence of heat cramps and heat exhaustion is likely. Heatstroke may follow extended activity.
Understanding the heat index involves considering values for shaded locales with light wind. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', determines the feeling of heat when you account for the relative humidity. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it's vital to remain hydrated, particularly during prolonged physical activities.
Evaporating sweat, an outcome of perspiration, is key in assisting the human body to moderate its temperature. With an abundance of moisture present in the air, the process of evaporation becomes less effective, and the body fails to cool down as it should, leading to the sensation of overheating. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

February, September and December, with an average relative humidity of 80%, are the most humid months.

Rainfall

In Donaldsonville, in September, during 17.9 rainfall days, 2.01" (51mm) of precipitation is typically accumulated. Throughout the year, there are 165.4 rainfall days, and 26.93" (684mm) of precipitation is accumulated.

Snowfall

February through December are months without snowfall.

Daylight

In September, the average length of the day is 12h and 20min.
On the first day of September, sunrise is at 6:41 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:50 pm CDT.

Sunshine

In Donaldsonville, the average sunshine in September is 9.7h.

UV index

The average daily maximum UV index in September in Donaldsonville is 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV radiation for the average person.
Note: In September, a regular UV index of 6 translates into these guidelines:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.

Frequently asked questions

How hot is September?

An average high-temperature, in September, in Donaldsonville, is 87.3°F (30.7°C) and the average low-temperature is 70.5°F (21.4°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in September is appraised at 104°F (40°C).

What are the most humid months?

The months with the highest humidity are February, September and December, with an average relative humidity of 80%.

What is the average humidity in September?

In September, the average relative humidity is 80%.

How many days does it rain in September?

In Donaldsonville, in September, it is raining for 17.9 days, with typically 2.01" (51mm) of accumulated precipitation.

When it does not snow?

In Donaldsonville, snow does not fall in February through December.

How many hours of daylight does Donaldsonville have in September?

The average day length in September is 12h and 20min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:41 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:50 pm CDT.

How long on average sun shines in September?

The average sunshine duration in September is 9.7h.

What is the UV index reading in September?

In Donaldsonville, the average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Donaldsonville, LA

Average temperature in September - Donaldsonville, LA
  • Average high temperature in September: 87.3°F

The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (60.1°F).

  • Average low temperature in September: 70.5°F

The month with the highest average low temperature is August (74.8°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).

Average pressure in September
Donaldsonville, LA

Average pressure in September - Donaldsonville, LA
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The months with the lowest atmospheric pressure are June and August (29.96"Hg).

Average wind speed in September
Donaldsonville, LA

Average wind speed in September - Donaldsonville, LA
  • Average wind speed in September: 5mph

The windiest month (with the highest average wind speed) is February (7.3mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).

Average humidity in September
Donaldsonville, LA

Average humidity in September - Donaldsonville, LA
  • Average humidity in September: 80%

The months with the highest relative humidity are February, September and December (80%).
The month with the lowest relative humidity is October (74%).

Average rainfall in September
Donaldsonville, LA

Average rainfall in September - Donaldsonville, LA
  • Average rainfall in September: 2.01"

The wettest month (with the highest rainfall) is July (4.25").
The driest month (with the least rainfall) is November (1.18").

Average rainfall days in September
Donaldsonville, LA

Average rainfall days in September - Donaldsonville, LA
  • Average rainfall days in September: 17.9 days

The month with the highest number of rainy days is July (21.3 days).
The month with the least rainy days is November (8.1 days).

Average snowfall in September
Donaldsonville, LA

Average snowfall in September - Donaldsonville, LA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.16").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in September
Donaldsonville, LA

Average snowfall days in September - Donaldsonville, LA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (0.2 days).
The months with the least snowfall days are February, March, April, May, June, July, August, September, October and November (0 days).

Average daylight in September /
Average sunshine in September
Donaldsonville, LA

Average daylight in September / Average sunshine in September - Donaldsonville, LA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).

  • Average sunshine in September: 9h and 4min

The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).

Average sunshine days in September
Donaldsonville, LA

Average sunshine days in September - Donaldsonville, LA
  • Average sunshine days in September: 9.9 days

The month with the most sunshine days is November (20.3 days).
The month with the least sunshine days is July (7.3 days).

Average UV index in September
Donaldsonville, LA

Average UV index in September - Donaldsonville, LA
  • Average UV index in September: 6

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

Average cloud cover in September
Donaldsonville, LA

Average cloud cover in September - Donaldsonville, LA
  • Average cloud cover in September: 30

The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is October (Cloud cover 27).

Average visibility in September
Donaldsonville, LA

Average visibility in September - Donaldsonville, LA
  • Average visibility in September: 5mi

The months with the highest visibility are January, February, June, August, October, November and December (6mi).
The months with the lowest visibility are March, April, May, July and September (5mi).

Donaldsonville, Louisiana, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location