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
The transition into September subtly indicates a reduction in the average high-temperature, down to an agreeable 73°F (22.8°C) from August's warm 78.6°F (25.9°C). September brings Castle Grove a consistent average low-temperature of 54.3°F (12.4°C).Humidity
In September, the average relative humidity is 79%.Rainfall
In Castle Grove, in September, it is raining for 11.4 days, with typically 2.52" (64mm) of accumulated precipitation. In Castle Grove, Iowa, during the entire year, the rain falls for 142.5 days and collects up to 28.27" (718mm) of precipitation.Snowfall
In Castle Grove, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:38 pm. On the last day of September, in Castle Grove, sunrise is at 7:02 am and sunset at 6:47 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In Castle Grove, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 4 translates into these guidelines:
Make use of precautions - Suggestions to resist sunburn are communicated. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Frequently asked questions
What are the temperatures in Castle Grove in September?
What is the average humidity in September in Castle Grove?
How much does it rain in Castle Grove in September?
When it does not snow in Castle Grove?
Does it snow in Castle Grove in September?
How many hours of daylight does Castle Grove have in September?
When is the sunrise / sunset in September in Castle Grove?
How many hours of sunshine does Castle Grove have in September?
What is the UV index intensity in September in Castle Grove?
Average temperature in September
Castle Grove, IA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (25.2°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).
Average pressure in September
Castle Grove, 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 (29.9"Hg).
Average wind speed in September
Castle Grove, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity in September
Castle Grove, IA
- Average humidity in September: 79%
The months with the highest relative humidity are January and February (86%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Castle Grove, IA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.25").
The driest months (with the least rainfall) are January and February (1.26").
Average rainfall days in September
Castle Grove, IA
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is January (5.2 days).
Average snowfall in September
Castle Grove, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.04").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Castle Grove, IA
- 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 May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Castle Grove, 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 months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Castle Grove, IA
- Average sunshine days in September: 17 days
The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in September
Castle Grove, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Castle Grove, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Castle Grove, 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).
Castle Grove, Iowa, USA
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