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
During the shift to September, Hopkinton records a mild decrease in average high-temperature, moving from a warm 78.6°F (25.9°C) in August to a pleasant 73°F (22.8°C). During September, the average low-temperature is a fresh 54.3°F (12.4°C).Humidity
In Hopkinton, the average relative humidity in September is 79%.Rainfall
In Hopkinton, in September, during 11.4 rainfall days, 2.52" (64mm) of precipitation is typically accumulated. Throughout the year, there are 142.5 rainfall days, and 28.27" (718mm) of precipitation is accumulated.Snowfall
In Hopkinton, snow does not fall in May through September.Daylight
In September, the average length of the day 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, sunrise is at 7:01 am and sunset at 6:47 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In Hopkinton, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: A daily maximum UV index of 4 in September translates into the following instructions:
Put precautions into practice - Protective measures against sun-induced damage are advised. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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 much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Hopkinton have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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 6min).
- 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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
Hopkinton, 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).
Hopkinton, Iowa, USA
Weather forecast for your location
2. Allow the app to use your location