September weather forecast
Holbrook, IA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Holbrook, Iowa, with an average temperature ranging between min 55.6°F (13.1°C) and max 74.8°F (23.8°C).

Temperature

During the shift to September, a minor reduction in average high-temperature is observed, shifting from a warm 80.6°F (27°C) in August to a still moderately hot 74.8°F (23.8°C). Nighttime temperature experiences an average drop to a mild 55.6°F (13.1°C) in September.

Humidity

In Holbrook, the average relative humidity in September is 77%.

Rainfall

In Holbrook, in September, during 12.5 rainfall days, 2.64" (67mm) of precipitation is typically accumulated. In Holbrook, during the entire year, the rain falls for 142 days and collects up to 29.09" (739mm) of precipitation.

Snowfall

In Holbrook, snow does not fall in June through September.

Daylight

In Holbrook, the average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:34 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:50 pm CDT.

Sunshine

The average sunshine in September is 9.3h.

UV index

In Holbrook, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum high UV index of 4 in September translates into the following recommendations:
Exercise prevention - Warding off sunburn is urged. Direct Sun exposure should be minimized especially during midday when radiation is most intense. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Updated: Jun 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Holbrook in September?

Holbrook in September has an average high-temperature of 74.8°F (23.8°C) and an average low-temperature of 55.6°F (13.1°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in August is calculated to be 86°F (30°C).

What is the average humidity in September?

In Holbrook, the average relative humidity in September is 77%.

How much does it rain in September?

In Holbrook, in September, during 12.5 rainfall days, 2.64" (67mm) of precipitation is typically accumulated.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

In Holbrook, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Holbrook have in September?

In September, the average day length is 12h and 28min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:34 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:50 pm CDT.

How many hours of sunshine does Holbrook have in September?

The average sunshine duration in September is 9.3h.

How high is the UV index in September in Holbrook?

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium health risk from 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
Holbrook, IA

Average temperature in September - Holbrook, IA
  • Average high temperature in September: 74.8°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (27.1°F).

  • Average low temperature in September: 55.6°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).

Average pressure in September
Holbrook, IA

Average pressure in September - Holbrook, IA
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in September
Holbrook, IA

Average wind speed in September - Holbrook, IA
  • Average wind speed in September: 8mph

The windiest months (with the highest average wind speed) are January and April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).

Average humidity in September
Holbrook, IA

Average humidity in September - Holbrook, IA
  • Average humidity in September: 77%

The months with the highest relative humidity are January and July (84%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Holbrook, IA

Average rainfall in September - Holbrook, IA
  • Average rainfall in September: 2.64"

The wettest month (with the highest rainfall) is May (4.33").
The driest month (with the least rainfall) is January (1.18").

Average rainfall days in September
Holbrook, IA

Average rainfall days in September - Holbrook, IA
  • Average rainfall days in September: 12.5 days

The months with the highest number of rainy days are May and June (18.5 days).
The month with the least rainy days is February (4.3 days).

Average snowfall in September
Holbrook, IA

Average snowfall in September - Holbrook, IA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (4.8").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Holbrook, IA

Average snowfall days in September - Holbrook, IA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (9.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Holbrook, IA

Average daylight in September / Average sunshine in September - Holbrook, IA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in September
Holbrook, IA

Average sunshine days in September - Holbrook, IA
  • Average sunshine days in September: 16 days

The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is June (9.1 days).

Average UV index in September
Holbrook, IA

Average UV index in September - Holbrook, 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
Holbrook, IA

Average cloud cover in September - Holbrook, IA
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 30).

Average visibility in September
Holbrook, IA

Average visibility in September - Holbrook, IA
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).

Holbrook, Iowa, USA

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