September weather forecastJamestown, LA
September
Weather in September
September, the first month of the autumn in Jamestown, is still a hot month, with an average temperature ranging between max 88.5°F (31.4°C) and min 67.3°F (19.6°C).Temperature
The transition to September results in a modest reduction in average high-temperature, moving from 94.6°F (34.8°C) in August to a still tropical 88.5°F (31.4°C). During the month of September, the temperature generally drops to a low average of 67.3°F (19.6°C).Heat index
The heat index value during September is evaluated at a torrid 102.2°F (39°C). Undertake additional safety actions, risk of heat cramps and heat exhaustion is significant. Persistent activity may induce heatstroke.Metrics for the heat index primarily focus on shaded spots and light wind conditions. The presence of direct sunlight can raise the heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', blends air temperature and moisture content to represent the felt temperature to humans. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.
Through perspiration, the body has a natural mechanism to eliminate excessive heat via sweat evaporation. An increase in relative humidity hinders the body's normal cooling function by reducing evaporation, thereby decreasing the rate of body cooling and enhancing the sense of warmth. When body heat isn't effectively managed, risks of dehydration and overheating amplify.
Humidity
The average relative humidity in September is 71%.Rainfall
July and September are months with the least rain when the rain falls for 14.1 days and typically aggregates up to 2.52" (64mm) of rain.Snowfall
In Jamestown, snow does not fall in April through November.Daylight
In Jamestown, the average length of the day in September is 12h and 21min.On the first day of September, sunrise is at 6:48 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:58 pm CDT.
Sunshine
The average sunshine in September in Jamestown is 9.4h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index of 5 during September translates into these guidelines:
Be vigilant - Preventing sunburn is recommended. It's recommended to limit sun exposure when its radiation is at its peak during midday. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Jamestown, LA
- Average high temperature in September: 88.5°F
The warmest months (with the highest average high temperature) are July and August (94.6°F).
The month with the lowest average high temperature is January (54.1°F).
- Average low temperature in September: 67.3°F
The month with the highest average low temperature is July (73.2°F).
The coldest month (with the lowest average low temperature) is January (38.5°F).
Average pressure in September
Jamestown, LA
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Jamestown, LA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is April (7.1mph).
The calmest months (with the lowest average wind speed) are July and August (4.9mph).
Average humidity in September
Jamestown, LA
- Average humidity in September: 71%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is August (69%).
Average rainfall in September
Jamestown, LA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.17").
The driest months (with the least rainfall) are July and September (2.52").
Average rainfall days in September
Jamestown, LA
- Average rainfall days in September: 14.1 days
The month with the highest number of rainy days is March (15.6 days).
The month with the least rainy days is October (9.5 days).
Average snowfall in September
Jamestown, LA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.47").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Jamestown, LA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.1 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Jamestown, LA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 12min).
The month with the shortest days is December (Average daylight: 10h and 6min).
- Average sunshine in September: 9h and 24min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).
Average sunshine days in September
Jamestown, LA
- Average sunshine days in September: 14 days
The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is February (12.9 days).
Average UV index in September
Jamestown, LA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January and December (UV index 3).
Average cloud cover in September
Jamestown, LA
- Average cloud cover in September: 29
The month with the most cloud cover is February (Cloud cover 51).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in September
Jamestown, LA
- Average visibility in September: 6mi
The months with the highest visibility are June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March, April, May and December (5mi).





