September weather forecast
Grand Rapids, OR

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Weather in September

September, the first month of the autumn in Grand Rapids, is also an agreeable month, with an average temperature fluctuating between 70.3°F (21.3°C) and 47.7°F (8.7°C).

Temperature

September's onset brings a negligible change in high-temperatures, falling from a moderately hot 77°F (25°C) in August to a pleasant 70.3°F (21.3°C). Throughout September, Grand Rapids acknowledges a distinct difference between its daytime highs and the steady low average of 47.7°F (8.7°C).

Humidity

In September, the average relative humidity is 79%.

Rainfall

In Grand Rapids, during September, the rain falls for 12.2 days and regularly aggregates up to 1.81" (46mm) of precipitation. Throughout the year, there are 184.4 rainfall days, and 36.61" (930mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 31min.
On the first day of the month, sunrise is at 6:36 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:12 am and sunset at 6:55 pm PDT.

Sunshine

In Grand Rapids, the average sunshine in September is 8.4h.

UV index

The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 3 in September interprets into the following recommendations:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.

Frequently asked questions

What is the average September temperature?

During September, Grand Rapids experiences an average high-temperature of 70.3°F (21.3°C) and a low-temperature of 47.7°F (8.7°C).

What is the average humidity in September?

In Grand Rapids, the average relative humidity in September is 79%.

How many days does it rain in September?

In Grand Rapids, during September, the rain falls for 12.2 days and regularly aggregates up to 1.81" (46mm) of precipitation.

When it does not snow?

In Grand Rapids, snow does not fall in May through October.

How many hours of daylight does Grand Rapids have in September?

The average day length in September is 12h and 31min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:36 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:55 pm PDT.

How many hours of sunshine does Grand Rapids have in September?

In September, the average sunshine duration is 8.4h.

What is the UV index reading in September?

In Grand Rapids, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Grand Rapids, OR

Average temperature in September - Grand Rapids, OR
  • Average high temperature in September: 70.3°F

The warmest month (with the highest average high temperature) is August (77°F).
The month with the lowest average high temperature is December (42.1°F).

  • Average low temperature in September: 47.7°F

The month with the highest average low temperature is August (50.7°F).
The coldest month (with the lowest average low temperature) is December (32.9°F).

Average pressure in September
Grand Rapids, OR

Average pressure in September - Grand Rapids, OR
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are August and September (30.02"Hg).

Average wind speed in September
Grand Rapids, OR

Average wind speed in September - Grand Rapids, OR
  • Average wind speed in September: 3.9mph

The windiest months (with the highest average wind speed) are January, March and November (4.8mph).
The calmest month (with the lowest average wind speed) is September (3.9mph).

Average humidity in September
Grand Rapids, OR

Average humidity in September - Grand Rapids, OR
  • Average humidity in September: 79%

The month with the highest relative humidity is November (89%).
The month with the lowest relative humidity is July (73%).

Average rainfall in September
Grand Rapids, OR

Average rainfall in September - Grand Rapids, OR
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is January (5.79").
The driest months (with the least rainfall) are July and August (0.51").

Average rainfall days in September
Grand Rapids, OR

Average rainfall days in September - Grand Rapids, OR
  • Average rainfall days in September: 12.2 days

The month with the highest number of rainy days is March (21.7 days).
The month with the least rainy days is July (6 days).

Average snowfall in September
Grand Rapids, OR

Average snowfall in September - Grand Rapids, OR
  • Average snowfall in September: 0"

The month with the highest snowfall is February (3.94").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Grand Rapids, OR

Average snowfall days in September - Grand Rapids, OR
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (4.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Grand Rapids, OR

Average daylight in September / Average sunshine in September - Grand Rapids, OR
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).

  • Average sunshine in September: 8h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 3h and 18min).

Average sunshine days in September
Grand Rapids, OR

Average sunshine days in September - Grand Rapids, OR
  • Average sunshine days in September: 15.6 days

The month with the most sunshine days is July (22.1 days).
The months with the least sunshine days are February and March (7.6 days).

Average UV index in September
Grand Rapids, OR

Average UV index in September - Grand Rapids, OR
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Grand Rapids, OR

Average cloud cover in September - Grand Rapids, OR
  • Average cloud cover in September: 43

The months with the most cloud cover are February and March (Cloud cover 67).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in September
Grand Rapids, OR

Average visibility in September - Grand Rapids, OR
  • Average visibility in September: 4mi

The months with the highest visibility are July and August (5mi).
The months with the lowest visibility are January, February, March, April, May, June, September, October, November and December (4mi).

Grand Rapids, Oregon, USA

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