January weather forecast
Issaquah, WA

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Weather in January

The weather in January in Issaquah, Washington is consistent with the beginning of the year. This month faces the highest levels of relative humidity, at 85%, and reduced daylight hours of 9. Erratic weather conditions prevail, combining cold temperatures, rainfall, and snowfall. On average, January has to offer 13.5 days with precipitation and 1.3 days with snowfall. This gloomy performance piece is illuminated by an average of 4.1 hours of sunshine daily.

Temperature

Issaquah's weather in January displays an average high-temperature of a frosty 44.2°F (6.8°C), showing minor disparity from December's 42.3°F (5.7°C). Issaquah's nighttime temperature in January drops to an average of 34.3°F (1.3°C).

Humidity

The months with the highest humidity in Issaquah are January and February, with an average relative humidity of 85%.

Rainfall

In January, the rain falls for 13.5 days. Throughout January, 1.85" (47mm) of precipitation is accumulated. In Issaquah, during the entire year, the rain falls for 127.4 days and collects up to 12.52" (318mm) of precipitation.

Snowfall

Months with snowfall in Issaquah are January through April, November and December. In January, in Issaquah, it is snowing for 1.3 days. Throughout January, 0.63" (16mm) of snow is accumulated. Throughout the year, there are 5.9 snowfall days, and 1.93" (49mm) of snow is accumulated.

Daylight

In Issaquah, the average length of the day in January is 8h and 58min.
On the first day of January, sunrise is at 7:55 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 5:07 pm PST.

Sunshine

In January, the average sunshine is 4.1h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: In January, the maximum UV index of 2 transforms into these recommendations:
Infants, children, and people with sensitive skin should always have protection against lengthy periods of sun exposure. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Updated: Aug 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is January cold?

In Issaquah, in January, the average high-temperature is 44.2°F (6.8°C), and the average low-temperature is 34.3°F (1.3°C).

What is the most humid month?

January and February, with an average relative humidity of 85%, are most humid months.

What is the average humidity in January?

The average relative humidity in January is 85%.

How many days does it rain in January?

In Issaquah, in January, during 13.5 rainfall days, 1.85" (47mm) of precipitation is typically accumulated.

How many days does it snow in January?

In Issaquah, in January, snow falls for 1.3 days, with typically accumulated 0.63" (16mm) of snow.

How many hours of daylight does Issaquah have in January?

In Issaquah, Washington, the average day length in January is 8h and 58min.

What time are sunrise and sunset in January?

On the first day of January, sunrise is at 7:55 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 5:07 pm PST.

How long on average sun shines in January?

In Issaquah, the average sunshine duration in January is 4.1h.

When is the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

What is the UV index intensity in January in Issaquah?

In January, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a minimal health vulnerability 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
Issaquah, WA

Average temperature in January - Issaquah, WA
  • Average high temperature in January: 44.2°F

The warmest month (with the highest average high temperature) is August (77°F).
The month with the lowest average high temperature is December (42.3°F).

  • Average low temperature in January: 34.3°F

The month with the highest average low temperature is August (51.4°F).
The coldest months (with the lowest average low temperature) are February and December (33.4°F).

Average pressure in January
Issaquah, WA

Average pressure in January - Issaquah, WA
  • Average pressure in January: 30.1"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

Average wind speed in January
Issaquah, WA

Average wind speed in January - Issaquah, WA
  • Average wind speed in January: 5.1mph

The windiest month (with the highest average wind speed) is January (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).

Average humidity in January
Issaquah, WA

Average humidity in January - Issaquah, WA
  • Average humidity in January: 85%

The months with the highest relative humidity are January and February (85%).
The month with the lowest relative humidity is July (69%).

Average rainfall in January
Issaquah, WA

Average rainfall in January - Issaquah, WA
  • Average rainfall in January: 1.85"

The wettest month (with the highest rainfall) is December (2.01").
The driest month (with the least rainfall) is July (0.24").

Average rainfall days in January
Issaquah, WA

Average rainfall days in January - Issaquah, WA
  • Average rainfall days in January: 13.5 days

The month with the highest number of rainy days is March (14.8 days).
The month with the least rainy days is August (4.3 days).

Average snowfall in January
Issaquah, WA

Average snowfall in January - Issaquah, WA
  • Average snowfall in January: 0.63"

The month with the highest snowfall is February (0.94").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in January
Issaquah, WA

Average snowfall days in January - Issaquah, WA
  • Average snowfall days in January: 1.3 days

The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in January /
Average sunshine in January
Issaquah, WA

Average daylight in January / Average sunshine in January - Issaquah, WA
  • Average daylight in January: 9h and 0min

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in January: 4h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 4h and 0min).

Average sunshine days in January
Issaquah, WA

Average sunshine days in January - Issaquah, WA
  • Average sunshine days in January: 15.8 days

The month with the most sunshine days is August (25 days).
The month with the least sunshine days is February (12.9 days).

Average UV index in January
Issaquah, WA

Average UV index in January - Issaquah, WA
  • Average UV index in January: 2

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in January
Issaquah, WA

Average cloud cover in January - Issaquah, WA
  • Average cloud cover in January: 58

The months with the most cloud cover are January and December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in January
Issaquah, WA

Average visibility in January - Issaquah, WA
  • Average visibility in January: 4mi

The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February and December (4mi).

Issaquah, Washington, USA

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