Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
Transitioning from August to September involves a subtle drop in average high-temperatures, descending from a moderately hot 77.5°F (25.3°C) to an agreeable 70.9°F (21.6°C). Nightly temperatures drop to an average low of 52°F (11.1°C) in September.Humidity
In September, the average relative humidity is 81%.Rainfall
In September, the rain falls for 9.8 days. Throughout September, 0.91" (23mm) of precipitation is accumulated. Throughout the year, there are 113.9 rainfall days, and 11.57" (294mm) of precipitation is accumulated.Snowfall
In Watertown, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:20 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:37 pm CDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
In September, the average daily maximum UV index is 3. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the maximum UV index of 3 translates into these guidelines:
Take necessary precautions - Defending against sun damage is advocated. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How many days does it rain in September in Watertown?
When it does not snow?
Does it snow in September?
How many hours of daylight does Watertown have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Watertown have in September?
What is the UV index reading in September?
Average temperature in September
Watertown, WI
- Average high temperature in September: 70.9°F
The warmest month (with the highest average high temperature) is July (78.6°F).
The month with the lowest average high temperature is January (23.7°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (11.7°F).
Average pressure in September
Watertown, WI
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Watertown, WI
- Average wind speed in September: 7.4mph
The windiest month (with the highest average wind speed) is April (10mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Watertown, WI
- Average humidity in September: 81%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is April (76%).
Average rainfall in September
Watertown, WI
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is July (1.54").
The driest months (with the least rainfall) are February and December (0.47").
Average rainfall days in September
Watertown, WI
- Average rainfall days in September: 9.8 days
The month with the highest number of rainy days is May (14.4 days).
The month with the least rainy days is February (3 days).
Average snowfall in September
Watertown, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.61").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Watertown, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Watertown, WI
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Watertown, WI
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is July (12.4 days).
Average UV index in September
Watertown, WI
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Watertown, WI
- Average cloud cover in September: 34
The month with the most cloud cover is January (Cloud cover 65).
The months with the least cloud cover are July, August and September (Cloud cover 34).
Average visibility in September
Watertown, WI
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Watertown, Wisconsin, USA
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