September weather forecast
Hartwick, IA

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Weather in September

The first month of the autumn, September, is still a warm month in Hartwick, Iowa, with an average temperature varying between 55.4°F (13°C) and 74.7°F (23.7°C).

Temperature

In September, Hartwick notes an average high-temperature of a still moderately hot 74.7°F (23.7°C), hardly different from the preceding month. September brings an average low-temperature of 55.4°F (13°C) to Hartwick.

Humidity

The average relative humidity in September in Hartwick, Iowa, is 77%.

Rainfall

In Hartwick, Iowa, in September, during 11.9 rainfall days, 2.72" (69mm) of precipitation is typically accumulated. In Hartwick, during the entire year, the rain falls for 135.6 days and collects up to 27.48" (698mm) of precipitation.

Snowfall

June through September are months without snowfall in Hartwick.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:36 am and sunset at 7:42 pm. On the last day of September, in Hartwick, sunrise is at 7:06 am and sunset at 6:52 pm CDT.

Sunshine

In Hartwick, the average sunshine in September is 9.3h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.
Note: The average daily UV index of 4 in September transforms into the following instructions:
Exercise prevention - Protecting skin and eyes from harm is required. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Hartwick in September?

The high-temperature, in September, in Hartwick, records 74.7°F (23.7°C), while the low-temperature is 55.4°F (13°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in July is evaluated at 87.8°F (31°C).

What is the average humidity in September in Hartwick?

The average relative humidity in September in Hartwick is 77%.

How many days does it rain in September in Hartwick?

In Hartwick, Iowa, in September, it is raining for 11.9 days, with typically 2.72" (69mm) of accumulated precipitation.

When it does not snow in Hartwick?

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

Does it snow in Hartwick in September?

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

How many hours of daylight does Hartwick have in September?

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

What time are sunrise and sunset in September in Hartwick?

In September, on the first day of the month, sunrise is at 6:36 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:52 pm CDT.

How many hours of sunshine does Hartwick have in September?

In Hartwick, Iowa, the average sunshine duration in September is 9.3h.

What is the UV index reading in September in Hartwick?

In Hartwick, Iowa, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability 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
Hartwick, IA

Average temperature in September - Hartwick, IA
  • Average high temperature in September: 74.7°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°F).

  • Average low temperature in September: 55.4°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 (13.6°F).

Average pressure in September
Hartwick, IA

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

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in September
Hartwick, IA

Average wind speed in September - Hartwick, IA
  • Average wind speed in September: 8.1mph

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

Average humidity in September
Hartwick, IA

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

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

Average rainfall in September
Hartwick, IA

Average rainfall in September - Hartwick, IA
  • Average rainfall in September: 2.72"

The wettest month (with the highest rainfall) is May (4.21").
The driest month (with the least rainfall) is January (1.02").

Average rainfall days in September
Hartwick, IA

Average rainfall days in September - Hartwick, IA
  • Average rainfall days in September: 11.9 days

The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is February (4.6 days).

Average snowfall in September
Hartwick, IA

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

The month with the highest snowfall is January (4.49").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Hartwick, IA

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

The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Hartwick, 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 2min

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

Average sunshine days in September
Hartwick, IA

Average sunshine days in September - Hartwick, IA
  • Average sunshine days in September: 16.5 days

The month with the most sunshine days is December (18.5 days).
The month with the least sunshine days is June (10.8 days).

Average UV index in September
Hartwick, IA

Average UV index in September - Hartwick, IA
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in September
Hartwick, IA

Average cloud cover in September - Hartwick, 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
Hartwick, IA

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

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

Hartwick, Iowa, USA

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