September weather forecast
Hillsboro, IA

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Weather in September

September, the first month of the autumn in Hillsboro, is still a warm month, with an average temperature ranging between max 76.3°F (24.6°C) and min 56.7°F (13.7°C).

Temperature

The move into September indicates a slight reduction in the average high-temperature, down from August's 81.7°F (27.6°C) to a still moderately hot 76.3°F (24.6°C). Hillsboro records a steady low-temperature average of 56.7°F (13.7°C) during September.

Humidity

In September, the average relative humidity is 75%.

Rainfall

In Hillsboro, in September, during 11.5 rainfall days, 2.56" (65mm) of precipitation is typically accumulated. Throughout the year, there are 140.1 rainfall days, and 29.92" (760mm) of precipitation is accumulated.

Snowfall

In Hillsboro, snow does not fall in May through September.

Daylight

In Hillsboro, the average length of the day in September is 12h and 27min.
On the first day of the month, sunrise is at 6:34 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:50 pm CDT.

Sunshine

The average sunshine in September is 9.3h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: An average maximum UV index of 4 in September leads to these recommendations:
Ensure safety - Imperative it is to shield skin and eyes from damage. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Updated: Aug 31, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Hillsboro in September?

In September, in Hillsboro, the average high-temperature is 76.3°F (24.6°C), and the average low-temperature is 56.7°F (13.7°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines relative humidity and air temperature, in August is estimated at 87.8°F (31°C).

What is the average humidity in September?

In September, the average relative humidity in Hillsboro, Iowa, is 75%.

How many days does it rain in September?

In Hillsboro, during September, the rain falls for 11.5 days and regularly aggregates up to 2.56" (65mm) of precipitation.

When it does not snow?

May through September are months without snowfall.

Does it snow in September?

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

What is the average length of the day in September in Hillsboro?

The average day length in September is 12h and 27min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:34 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:50 pm CDT.

How many hours of sunshine does Hillsboro have in September?

The average sunshine duration in September is 9.3h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health threat 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
Hillsboro, IA

Average temperature in September - Hillsboro, IA
  • Average high temperature in September: 76.3°F

The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in September: 56.7°F

The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).

Average pressure in September
Hillsboro, IA

Average pressure in September - Hillsboro, 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 (29.9"Hg).

Average wind speed in September
Hillsboro, IA

Average wind speed in September - Hillsboro, IA
  • Average wind speed in September: 7.9mph

The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).

Average humidity in September
Hillsboro, IA

Average humidity in September - Hillsboro, IA
  • Average humidity in September: 75%

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Hillsboro, IA

Average rainfall in September - Hillsboro, IA
  • Average rainfall in September: 2.56"

The wettest month (with the highest rainfall) is May (4.29").
The driest months (with the least rainfall) are February and December (1.38").

Average rainfall days in September
Hillsboro, IA

Average rainfall days in September - Hillsboro, IA
  • Average rainfall days in September: 11.5 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.6 days).

Average snowfall in September
Hillsboro, IA

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

The month with the highest snowfall is January (4.76").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Hillsboro, IA

Average snowfall days in September - Hillsboro, 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 May, June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Hillsboro, 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 18min).

  • 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 0min).

Average sunshine days in September
Hillsboro, IA

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

The month with the most sunshine days is October (18.4 days).
The month with the least sunshine days is May (10.6 days).

Average UV index in September
Hillsboro, IA

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

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

Average cloud cover in September
Hillsboro, IA

Average cloud cover in September - Hillsboro, IA
  • Average cloud cover in September: 31

The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July, August and September (Cloud cover 31).

Average visibility in September
Hillsboro, IA

Average visibility in September - Hillsboro, 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).

Hillsboro, Iowa, USA

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