Climate and monthly 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). 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. Weather in January »

Weather in February

The last month of the winter, February, is another comfortable month in Johnstown, California, with temperature in the range of an average low of 46°F (7.8°C) and an average high of 64.8°F (18.2°C). Entering February, the average high-temperature is recorded at a still enjoyable 64.8°F (18.2°C), exhibiting a minimal shift from January's 65.5°F (18.6°C). Weather in February »

Weather in March

March, the first month of the spring in Johnstown, is still a refreshing month, with an average temperature varying between 67.6°F (19.8°C) and 47.8°F (8.8°C). In March, Johnstown notes an average high-temperature of a still enjoyable 67.6°F (19.8°C), hardly different from the preceding month. Weather in March »

Weather in April

April is an agreeable spring month in Johnstown, California, with an average temperature ranging between max 70.5°F (21.4°C) and min 49.5°F (9.7°C). April registers an average high-temperature of a pleasant 70.5°F (21.4°C), slightly varied from March's 67.6°F (19.8°C). Weather in April »

Weather in May

May, the last month of the spring in Johnstown, is also an agreeable month, with temperature in the range of an average high of 72.5°F (22.5°C) and an average low of 52.7°F (11.5°C). The advent of May presents an average high-temperature of a still pleasant 72.5°F (22.5°C), maintaining a close correlation with the preceding month. Weather in May »

Weather in June

June, the first month of the summer in Johnstown, is a moderately hot month, with an average temperature fluctuating between 56.8°F (13.8°C) and 78.4°F (25.8°C). June marks a minor ascent in the average high-temperature, adjusting from May's agreeable 72.5°F (22.5°C) to a moderately hot 78.4°F (25.8°C). Weather in June »

Weather in July

July, the same as June, is a moderately hot summer month in Johnstown, California, with an average temperature fluctuating between 83.7°F (28.7°C) and 63.1°F (17.3°C). In July, the average high-temperature registers at a still warm 83.7°F (28.7°C), nearly identical to June's 78.4°F (25.8°C). Weather in July »

Weather in August

August, the last month of the summer in Johnstown, is another warm month, with an average temperature varying between 85.5°F (29.7°C) and 64.9°F (18.3°C). Johnstown's warmest month, August, generally records average temperatures ranging from a high of 85.5°F (29.7°C) to a low of 64.9°F (18.3°C). The heat index value for August is computed to be a hot 89.6°F (32°C). Weather in August »

Weather in September

September, the first month of the autumn in Johnstown, is also a moderately hot month, with an average temperature varying between 63.5°F (17.5°C) and 83.3°F (28.5°C). Johnstown's September reports an average high-temperature of a still warm 83.3°F (28.5°C), exhibiting a minor difference from August. Weather in September »

Weather in October

October, the same as September, is a moderately hot autumn month in Johnstown, California, with an average temperature fluctuating between 77.5°F (25.3°C) and 57.7°F (14.3°C). Transition into October subtly marks a drop in the average high-temperature, moderately moving from 83.3°F (28.5°C) in September to a still warm 77.5°F (25.3°C). Weather in October »

Weather in November

The last month of the autumn, November, is another pleasant month in Johnstown, California, with an average temperature fluctuating between 71.2°F (21.8°C) and 51.6°F (10.9°C). The beginning of November brings a slight decrease in the average high-temperature, transitioning from a warm 77.5°F (25.3°C) in October to a pleasant 71.2°F (21.8°C). Weather in November »

Weather in December

December, the first month of the winter in Johnstown, is also an enjoyable month, with an average temperature fluctuating between 63.7°F (17.6°C) and 46.6°F (8.1°C). With average high and low temperatures of 63.7°F (17.6°C) and 46.6°F (8.1°C) respectively, December is Johnstown's coldest month. Weather in December »
Updated: Jul 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How much does it rain in Johnstown?

In Johnstown, during the entire year, the rain falls for 49.6 days and collects up to 5.16" (131mm) of precipitation.

What is the wettest month?

The month with the most rainfall is February, when the rain falls for 5.1 days and typically aggregates up to 1.06" (27mm) of precipitation.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.

What is the most humid month?

May is the most humid month, with an average relative humidity of 65%.

What is the driest month?

The month with the least rainfall in Johnstown is June, when the rain falls for 1.4 days and typically collects 0.04" (1mm) of precipitation.

When are the longest days?

The month with the longest days is June, with an average of 14h and 18min of daylight.

What is the month with the most sunshine?

June and July, with an average of 12.1h of sunshine, are months with the most sunshine.

What are the months with the highest UV index?

The months with the highest UV index in Johnstown are June through September, with an average maximum UV index of 6.

What are the warmest months?

In Johnstown, August is the month with the highest recorded average temperatures, measuring a high of 85.5°F (29.7°C) and a low of 64.9°F (18.3°C).

What is the least humid month?

November is the least humid month, with an average relative humidity of 52%.

What is the coldest month?

December, with an average high of 63.7°F (17.6°C) and a low of 46.6°F (8.1°C), signifies the coldest month of the year.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 10h and 0min of daylight.

What is the month with the least sunshine?

With an average of 6.7h of sunshine, December has the least sunshine of the year.

When is the lowest UV index?

December is the month with the lowest UV index, with an average maximum UV index of 3.

Average temperature
Johnstown, CA

Average temperature - Johnstown, CA

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).

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
Johnstown, CA

Average pressure - Johnstown, CA

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
Johnstown, CA

Average wind speed - Johnstown, CA

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
Johnstown, CA

Average humidity - Johnstown, CA

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

Average rainfall
Johnstown, CA

Average rainfall - Johnstown, CA

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
Johnstown, CA

Average rainfall days - Johnstown, CA

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 / Average sunshine
Johnstown, CA

Average daylight / Average sunshine - Johnstown, CA

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).

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
Johnstown, CA

Average sunshine days - Johnstown, CA

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
Johnstown, CA

Average UV index - Johnstown, CA

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 visibility
Johnstown, CA

Average visibility - Johnstown, CA

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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