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
With the arrival of September, Grand Rapids notices a mild change in the average high-temperature, sliding from August's moderately hot 78.6°F (25.9°C) to a pleasant 72°F (22.2°C). Throughout September, the temperature tends to fall to a consistent average low of 54°F (12.2°C).Humidity
In Grand Rapids, the average relative humidity in September is 77%.Rainfall
In Grand Rapids, during September, the rain falls for 6.6 days and regularly aggregates up to 0.63" (16mm) of precipitation. Throughout the year, there are 103.5 rainfall days, and 9.02" (229mm) of precipitation is accumulated.Snowfall
In Grand Rapids, snow does not fall in May through October.Daylight
In Grand Rapids, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 7:08 am and sunset at 8:16 pm. On the last day of September, sunrise is at 7:39 am and sunset at 7:25 pm EDT.
Sunshine
The average sunshine in September is 8.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, an average UV index of 4 transforms into the following instructions:
Be vigilant - Preventing sunburn is recommended. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
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?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September in Grand Rapids?
How many hours of sunshine does Grand Rapids have in September?
What is the UV index reading in September?
Average temperature in September
Grand Rapids, MI
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (18.7°F).
Average pressure in September
Grand Rapids, MI
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Grand Rapids, MI
- Average wind speed in September: 7.4mph
The windiest month (with the highest average wind speed) is April (9.8mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in September
Grand Rapids, MI
- Average humidity in September: 77%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is April (75%).
Average rainfall in September
Grand Rapids, MI
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is May (1.14").
The driest month (with the least rainfall) is March (0.47").
Average rainfall days in September
Grand Rapids, MI
- Average rainfall days in September: 6.6 days
The month with the highest number of rainy days is May (13 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in September
Grand Rapids, MI
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.57").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Grand Rapids, MI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.5 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
Grand Rapids, MI
- 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 6min).
- Average sunshine in September: 8h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 2h and 18min).
Average sunshine days in September
Grand Rapids, MI
- Average sunshine days in September: 21 days
The month with the most sunshine days is September (21 days).
The month with the least sunshine days is April (13.4 days).
Average UV index in September
Grand Rapids, MI
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Grand Rapids, MI
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 75).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Grand Rapids, MI
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
Grand Rapids, Michigan, USA
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