January weather forecast
Sioux City, IA

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Panorama of the vast Sioux City, Iowa
Panorama of the vast Sioux City, Iowa

Weather in January

After the relative calm of December, January ushers in the new year with a noticeable drop in temperature reaching a high of 27°F (-2.8°C) and a low of 13.5°F (-10.3°C). High relative humidity, reaching 83%, indicates that the cold bites more than the thermometer might suggest. Sioux City residents should prepare for snowy conditions, as the city experiences its fair share of snowflake showers. Dress in layers and pay attention to frostbite warnings during particularly chill nights. Despite these conditions, the shorter days with 9.5 hours of daylight and reduced sunshine brings a stark beauty to the city not seen in other months.

Temperature

Sioux City, Iowa, witnesses the coldest weather in January, with temperatures averaging a high of 27°F (-2.8°C) and a low of 13.5°F (-10.3°C).

Humidity

With an average relative humidity of 83%, January is the most humid month.

Rainfall

January and February are months with the least rain when the rain falls for 2.6 days and typically aggregates up to 0.39" (10mm) of rain.

Snowfall

Months with snowfall are January through April, October through December. January is the month with the most snowfall. Snow falls for 8.2 days and accumulates 1.77" (45mm) of snow.

Daylight

In Sioux City, the average length of the day in January is 9h and 29min.
On the first day of the month, sunrise is at 7:55 am and sunset at 5:02 pm. On the last day of January, sunrise is at 7:40 am and sunset at 5:37 pm CST.

Sunshine

With an average of 4.5h of sunshine, January has the least sunshine of the year.

UV index

With an average maximum UV index of 1, January is the month with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for the average person.
Note: A daily high UV index of 1 in January leads to these guidelines:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Updated: Jun 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest month in Sioux City?

The month of January, characterized by an average high of 27°F (-2.8°C) and a low of 13.5°F (-10.3°C), is recognized as the coldest.

How cold is January in Sioux City?

The high-temperature during January is 27°F (-2.8°C) and the low-temperature is 13.5°F (-10.3°C).

What is the most humid month?

The most humid month is January, with an average relative humidity of 83%.

What is the average humidity in January in Sioux City?

In January, the average relative humidity is 83%.

What is the driest month?

The months with the least rainfall are January and February Rain falls for 2.6 days and accumulates 0.39" (10mm) of rain.

How much does it rain in January?

In Sioux City, during January, the rain falls for 2.6 days and regularly aggregates up to 0.39" (10mm) of precipitation.

What is the snowiest month?

The month with the most snowfall is January, when snow falls for 8.2 days and typically aggregates up to 1.77" (45mm) of snow.

How many days does it snow in January?

In Sioux City, in January, during 8.2 snowfall days, 1.77" (45mm) of snow is typically accumulated.

What is the average length of the day in January?

In Sioux City, the average day length in January is 9h and 29min.

When are sunrise and sunset in January?

On the first day of January, sunrise is at 7:55 am and sunset at 5:02 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 5:37 pm CST.

What is the month with the least sunshine?

With an average of 4.5h of sunshine, January has the least sunshine of the year.

How many hours of sunshine does Sioux City have in January?

In Sioux City, the average sunshine duration in January is 4.5h.

What is the month with the lowest UV index?

January is the month with the lowest UV index, with an average maximum UV index of 1.

What is the UV index intensity in January?

The average daily maximum UV index in January is 1. A UV Index value of 2, and less, symbolizes a low health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Sioux City, IA

Average temperature in January - Sioux City, IA
  • Average high temperature in January: 27°F

The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (27°F).

  • Average low temperature in January: 13.5°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).

Average pressure in January
Sioux City, IA

Average pressure in January - Sioux City, IA
  • Average pressure in January: 30.16"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).

Average wind speed in January
Sioux City, IA

Average wind speed in January - Sioux City, IA
  • Average wind speed in January: 10.7mph

The windiest month (with the highest average wind speed) is April (11mph).
The calmest month (with the lowest average wind speed) is July (7.5mph).

Average humidity in January
Sioux City, IA

Average humidity in January - Sioux City, IA
  • Average humidity in January: 83%

The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (65%).

Average rainfall in January
Sioux City, IA

Average rainfall in January - Sioux City, IA
  • Average rainfall in January: 0.39"

The wettest month (with the highest rainfall) is June (1.85").
The driest months (with the least rainfall) are January and February (0.39").

Average rainfall days in January
Sioux City, IA

Average rainfall days in January - Sioux City, IA
  • Average rainfall days in January: 2.6 days

The month with the highest number of rainy days is June (14.6 days).
The month with the least rainy days is January (2.6 days).

Average snowfall in January
Sioux City, IA

Average snowfall in January - Sioux City, IA
  • Average snowfall in January: 1.77"

The month with the highest snowfall is January (1.77").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in January
Sioux City, IA

Average snowfall days in January - Sioux City, IA
  • Average snowfall days in January: 8.2 days

The month with the highest number of snowfall days is January (8.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in January /
Average sunshine in January
Sioux City, IA

Average daylight in January / Average sunshine in January - Sioux City, IA
  • Average daylight in January: 9h 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 6min).

  • Average sunshine in January: 4h and 3min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).

Average sunshine days in January
Sioux City, IA

Average sunshine days in January - Sioux City, IA
  • Average sunshine days in January: 22.6 days

The month with the most sunshine days is January (22.6 days).
The month with the least sunshine days is June (13.1 days).

Average UV index in January
Sioux City, IA

Average UV index in January - Sioux City, IA
  • Average UV index in January: 1

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 January
Sioux City, IA

Average cloud cover in January - Sioux City, IA
  • Average cloud cover in January: 51

The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 25).

Average visibility in January
Sioux City, IA

Average visibility in January - Sioux City, IA
  • Average visibility in January: 6mi

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

Sioux City, Iowa, USA

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