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
Princeton's September weather features a light decline in high-temperatures, reducing from a warm 80.1°F (26.7°C) in August to a still moderately hot 74.1°F (23.4°C). The average nighttime temperature lowers to a fresh 55°F (12.8°C) throughout September.Humidity
In September, the average relative humidity in Princeton is 77%.Rainfall
In Princeton, Iowa, in September, during 11.5 rainfall days, 2.36" (60mm) of precipitation is typically accumulated. In Princeton, during the entire year, the rain falls for 146.6 days and collects up to 28.86" (733mm) of precipitation.Snowfall
In Princeton, snow does not fall in May through September.Daylight
The average length of the day in September in Princeton is 12h and 28min.On the first day of September in Princeton, sunrise is at 6:28 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm CDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, an average UV index of 4 transforms into the following instructions:
Take necessary precautions - Defending against sun damage is advocated. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Frequently asked questions
What is the average September temperature in Princeton?
What is the average humidity in September in Princeton?
How many days does it rain in September in Princeton?
When it does not snow in Princeton?
Does it snow in Princeton in September?
What is the average length of the day in September in Princeton?
When is the sunrise / sunset in September in Princeton?
How long on average sun shines in September in Princeton?
How high is the UV index in September in Princeton?
Average temperature in September
Princeton, IA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (26.8°F).
- Average low temperature in September: 55°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (14.4°F).
Average pressure in September
Princeton, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Princeton, IA
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in September
Princeton, IA
- Average humidity in September: 77%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Princeton, IA
- Average rainfall in September: 2.36"
The wettest month (with the highest rainfall) is May (4.45").
The driest months (with the least rainfall) are January and February (1.34").
Average rainfall days in September
Princeton, IA
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is February (5.5 days).
Average snowfall in September
Princeton, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.8").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Princeton, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Princeton, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Princeton, IA
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Princeton, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Princeton, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 58).
The months with the least cloud cover are August and September (Cloud cover 30).
Average visibility in September
Princeton, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).
Princeton, Iowa, USA
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