January weather forecast
Johnstown, CA

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Weather in January

January, like December, in Johnstown, California, is another refreshing winter month, with an average temperature varying between 65.5°F (18.6°C) and 46.6°F (8.1°C).

Temperature

As January unfolds, the average high-temperature reaches a still enjoyable 65.5°F (18.6°C), hinting at a slight fluctuation from the previous month. During the month of January, Johnstown experiences a steady low-temperature average of 46.6°F (8.1°C).

Humidity

In January, the average relative humidity is 55%.

Rainfall

In January, the rain falls for 4.7 days. Throughout January, 0.55" (14mm) of precipitation is accumulated. In Johnstown, during the entire year, the rain falls for 49.6 days and collects up to 5.16" (131mm) of precipitation.

Daylight

The average length of the day in January is 10h and 17min.
On the first day of the month, sunrise is at 6:50 am and sunset at 4:52 pm. On the last day of January, sunrise is at 6:43 am and sunset at 5:18 pm PST.

Sunshine

The average sunshine in January is 6.9h.

UV index

The average daily maximum UV index in January is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: In January, the maximum UV index of 4 translates into these guidelines:
Act with care - Obligation to protect against skin and eye damage is highlighted. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Updated: Jul 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are January temperatures?

In Johnstown, in January, the average high-temperature is 65.5°F (18.6°C), and the average low-temperature is 46.6°F (8.1°C).

What is the average humidity in January?

In Johnstown, the average relative humidity in January is 55%.

How much does it rain in January?

In Johnstown, in January, during 4.7 rainfall days, 0.55" (14mm) of precipitation is typically accumulated.

How many hours of daylight does Johnstown have in January?

In January, the average day length is 10h and 17min.

What time are sunrise and sunset in January?

In January, on the first day of the month, sunrise is at 6:50 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 6:43 am and sunset at 5:18 pm PST.

How many hours of sunshine does Johnstown have in January?

The average sunshine duration in January is 6.9h.

How high is the UV index in January?

In Johnstown, the average daily maximum UV index in January is 4. A UV Index value of 3 to 5 symbolizes a medium health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Johnstown, CA

Average temperature in January - Johnstown, CA
  • Average high temperature in January: 65.5°F

The warmest month (with the highest average high temperature) is August (85.5°F).
The month with the lowest average high temperature is December (63.7°F).

  • Average low temperature in January: 46.6°F

The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (46°F).

Average pressure in January
Johnstown, CA

Average pressure in January - Johnstown, CA
  • Average pressure in January: 30.09"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).

Average wind speed in January
Johnstown, CA

Average wind speed in January - Johnstown, CA
  • Average wind speed in January: 4.8mph

The windiest months (with the highest average wind speed) are April and May (5.3mph).
The calmest months (with the lowest average wind speed) are August, September and October (4.2mph).

Average humidity in January
Johnstown, CA

Average humidity in January - Johnstown, CA
  • Average humidity in January: 55%

The month with the highest relative humidity is May (65%).
The month with the lowest relative humidity is November (52%).

Average rainfall in January
Johnstown, CA

Average rainfall in January - Johnstown, CA
  • Average rainfall in January: 0.55"

The wettest month (with the highest rainfall) is February (1.06").
The driest month (with the least rainfall) is June (0.04").

Average rainfall days in January
Johnstown, CA

Average rainfall days in January - Johnstown, CA
  • Average rainfall days in January: 4.7 days

The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is June (1.4 days).

Average daylight in January /
Average sunshine in January
Johnstown, CA

Average daylight in January / Average sunshine in January - Johnstown, CA
  • Average daylight in January: 10h and 2min

The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in January: 6h and 5min

The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).

Average sunshine days in January
Johnstown, CA

Average sunshine days in January - Johnstown, CA
  • Average sunshine days in January: 25.1 days

The month with the most sunshine days is June (28 days).
The month with the least sunshine days is July (20.7 days).

Average UV index in January
Johnstown, CA

Average UV index in January - Johnstown, CA
  • Average UV index in January: 4

The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in January
Johnstown, CA

Average cloud cover in January - Johnstown, CA
  • Average cloud cover in January: 20

The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 6).

Average visibility in January
Johnstown, CA

Average visibility in January - Johnstown, CA
  • 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).

Johnstown, California, USA

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