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 start of September signals a gentle decrease in the average high-temperature, transitioning from a moderately hot 78.6°F (25.9°C) in August to an agreeable 73°F (22.8°C). An average nighttime temperature of 54.3°F (12.4°C) is noted during the month of September.Humidity
In Monticello, the average relative humidity in September is 79%.Rainfall
In September, the rain falls for 11.4 days. Throughout September, 2.52" (64mm) of precipitation is accumulated. In Monticello, during the entire year, the rain falls for 142.5 days and collects up to 28.27" (718mm) of precipitation.Snowfall
In Monticello, snow does not fall in May through September.Daylight
In Monticello, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:30 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:47 pm CDT.
Sunshine
The average sunshine in September in Monticello is 9.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 4 during September translates into the following directions:
Heed the precautions - Suggestions to avoid sunburn are made. It's recommended to limit sun exposure when its radiation is at its peak during midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow in Monticello?
Does it snow in September?
How many hours of daylight does Monticello have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Monticello have in September?
How high is the UV index in September in Monticello?
Average temperature in September
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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
Monticello, 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).
Monticello, Iowa, USA
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