January weather forecast
Napa Junction, SD

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Weather in January

January, the same as December, in Napa Junction, South Dakota, is a freezing cold winter month, with temperature in the range of an average low of 12.9°F (-10.6°C) and an average high of 26.8°F (-2.9°C).

Temperature

Napa Junction's coldest weather arrives in January, when temperatures average a high of 26.8°F (-2.9°C) and a low of 12.9°F (-10.6°C).

Humidity

The most humid month is January, with an average relative humidity of 85%.

Rainfall

In Napa Junction, in January, during 3.4 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. Throughout the year, there are 117.9 rainfall days, and 21.93" (557mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, October through December. In January, it is snowing for 9.7 days. Throughout January, 2.6" (66mm) of snow is accumulated. In Napa Junction, during the entire year, snow falls for 37.4 days and aggregates up to 14.45" (367mm) of snow.

Daylight

In Napa Junction, South Dakota, the average length of the day in January is 9h and 27min.
On the first day of the month, sunrise is at 8:00 am and sunset at 5:05 pm. On the last day of January, sunrise is at 7:45 am and sunset at 5:40 pm CST.

Sunshine

With an average of 4.4h of sunshine, January has the least sunshine of the year.

UV index

The month with the lowest UV index is January, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the ordinary person.
Note: In January, a regular UV index of 1 translates into these guidelines:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Updated: Jun 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest month?

January is the coldest month, with an average high-temperature of 26.8°F (-2.9°C) and an average low-temperature of 12.9°F (-10.6°C).

How cold is it in January?

The average high-temperature and low-temperature during January are 26.8°F (-2.9°C) and 12.9°F (-10.6°C) respectively.

What is the most humid month in Napa Junction?

The most humid month is January, with an average relative humidity of 85%.

What is the average humidity in January?

In January, the average relative humidity is 85%.

How many days does it rain in January?

In Napa Junction, in January, during 3.4 rainfall days, 0.67" (17mm) of precipitation is typically accumulated.

How many days does it snow in January?

In Napa Junction, in January, snow falls for 9.7 days, with typically accumulated 2.6" (66mm) of snow.

How many hours of daylight does Napa Junction have in January?

In Napa Junction, the average day length in January is 9h and 27min.

When are sunrise and sunset in January?

In January, on the first day of the month, sunrise is at 8:00 am and sunset at 5:05 pm. On the last day of the month, in Napa Junction, sunrise is at 7:45 am and sunset at 5:40 pm CST.

What is the month with the least sunshine?

With an average of 4.4h of sunshine, January has the least sunshine of the year.

How many hours of sunshine does Napa Junction have in January?

In January, the average sunshine duration in Napa Junction is 4.4h.

When is 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?

In January, the average daily maximum UV index is 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from 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
Napa Junction, SD

Average temperature in January - Napa Junction, SD
  • Average high temperature in January: 26.8°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (26.8°F).

  • Average low temperature in January: 12.9°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 (12.9°F).

Average pressure in January
Napa Junction, SD

Average pressure in January - Napa Junction, SD
  • 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 (29.85"Hg).

Average wind speed in January
Napa Junction, SD

Average wind speed in January - Napa Junction, SD
  • Average wind speed in January: 10.6mph

The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.9mph).

Average humidity in January
Napa Junction, SD

Average humidity in January - Napa Junction, SD
  • Average humidity in January: 85%

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (64%).

Average rainfall in January
Napa Junction, SD

Average rainfall in January - Napa Junction, SD
  • Average rainfall in January: 0.67"

The wettest month (with the highest rainfall) is May (3.78").
The driest month (with the least rainfall) is February (0.59").

Average rainfall days in January
Napa Junction, SD

Average rainfall days in January - Napa Junction, SD
  • Average rainfall days in January: 3.4 days

The month with the highest number of rainy days is June (17.4 days).
The month with the least rainy days is February (2.3 days).

Average snowfall in January
Napa Junction, SD

Average snowfall in January - Napa Junction, SD
  • Average snowfall in January: 2.6"

The month with the highest snowfall is December (2.95").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in January
Napa Junction, SD

Average snowfall days in January - Napa Junction, SD
  • Average snowfall days in January: 9.7 days

The month with the highest number of snowfall days is January (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in January /
Average sunshine in January
Napa Junction, SD

Average daylight in January / Average sunshine in January - Napa Junction, SD
  • Average daylight in January: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in January: 4h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in January
Napa Junction, SD

Average sunshine days in January - Napa Junction, SD
  • Average sunshine days in January: 19.3 days

The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (9.3 days).

Average UV index in January
Napa Junction, SD

Average UV index in January - Napa Junction, SD
  • Average UV index in January: 1

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 January
Napa Junction, SD

Average cloud cover in January - Napa Junction, SD
  • Average cloud cover in January: 52

The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 25).

Average visibility in January
Napa Junction, SD

Average visibility in January - Napa Junction, SD
  • 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).

Napa Junction, South Dakota, USA

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