Fullerton
California, USA
Long-term weather forecast
Long-term weather forecast

Monthly weather forecast and climate
Fullerton, CA

A scenic view of the trees and neat lawns of the famous Muckenthaler Community Center in Fullerton, California
A scenic view of the trees and neat lawns of the famous Muckenthaler Community Center in Fullerton, California
January, like December, in Fullerton, California, is another enjoyable winter month, with average temperature ranging between min 51.4°F (10.8°C) and max 66.2°F (19°C). In Fullerton, the average high-temperature is practically the same as in December - a still comfortable 66.2°F (19°C). Weather in January »

February, the last month of the winter, in Fullerton, is another comfortable month, with temperature in the range of an average high of 65.3°F (18.5°C) and an average low of 50.2°F (10.1°C). In Fullerton, the average high-temperature in February is essentially the same as in January - a still comfortable 65.3°F (18.5°C). Weather in February »

The first month of the spring, March, is also an enjoyable month in Fullerton, California, with average temperature ranging between min 52°F (11.1°C) and max 67.6°F (19.8°C). In Fullerton, the average high-temperature is practically the same as in February - a still comfortable 67.6°F (19.8°C). Weather in March »

April in Fullerton, California, is a pleasant spring month, with temperature in the range of an average high of 70.5°F (21.4°C) and an average low of 53.8°F (12.1°C). In April, the average high-temperature is almost the same as in March - an agreeable 70.5°F (21.4°C). Weather in April »

The last month of the spring, May, is also an agreeable month in Fullerton, California, with average temperature varying between 72.3°F (22.4°C) and 56.1°F (13.4°C). In May, the average high-temperature is almost the same as in April - a still pleasant 72.3°F (22.4°C). Weather in May »

June, the first month of the summer, in Fullerton, is a moderately hot month, with average temperature fluctuating between 58.8°F (14.9°C) and 76.6°F (24.8°C). In June, the average high-temperature is almost the same as in May - a warm 76.6°F (24.8°C). Weather in June »

July, the same as June, is another warm summer month in Fullerton, California, with average temperature varying between 81.5°F (27.5°C) and 63.9°F (17.7°C). In Fullerton, California, the average high-temperature is almost the same as in June - a still moderately hot 81.5°F (27.5°C). Weather in July »

August, the last month of the summer, in Fullerton, is also a moderately hot month, with average temperature ranging between max 83.5°F (28.6°C) and min 65.5°F (18.6°C). With an average high-temperature of 83.5°F (28.6°C) and an average low-temperature of 65.5°F (18.6°C), August is the warmest month. In August, the average heat index is estimated at a hot 86.4°F (30.2°C). Weather in August »

The first month of the autumn, September, is also a moderately hot month in Fullerton, California, with average temperature varying between 82.2°F (27.9°C) and 64.8°F (18.2°C). In September, the average high-temperature is almost the same as in August - a still moderately hot 82.2°F (27.9°C). Weather in September »

October, the same as September, is a moderately hot autumn month in Fullerton, California, with average temperature fluctuating between 61.5°F (16.4°C) and 77.5°F (25.3°C). In October, the average high-temperature is essentially the same as in September - a still moderately hot 77.5°F (25.3°C). Weather in October »

November, the last month of the autumn, in Fullerton, is also an agreeable month, with average temperature fluctuating between 71.4°F (21.9°C) and 56.3°F (13.5°C). In Fullerton, the average high-temperature slightly decreases, from a moderately hot 77.5°F (25.3°C) in October, to an agreeable 71.4°F (21.9°C). Weather in November »

The first month of the winter, December, is also an enjoyable month in Fullerton, California, with temperature in the range of an average low of 50.9°F (10.5°C) and an average high of 64°F (17.8°C). With an average high-temperature of 64°F (17.8°C) and an average low-temperature of 50.9°F (10.5°C), December is the coldest month. Weather in December »

How many days does it rain in Fullerton?

Throughout the year, there are 52.5 rainfall days, and 7.09" (180mm) of precipitation is accumulated.

What is the month with the lowest UV index in Fullerton?

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 4.

What is the most humid month in Fullerton?

With an average relative humidity of 65%, June is the most humid month.

What is the driest month in Fullerton?

The month with the least rainfall in Fullerton is June when the rain falls for 1.5 days and typically collects 0.04" (1mm) of precipitation.

When are the longest days in Fullerton?

With an average of 14.4h of daylight, June has the longest days of the year.

What is the month with the highest UV index in Fullerton?

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

What are the months with the most sunshine in Fullerton?

July and August, with an average of 12h of sunshine, are months with the most sunshine in Fullerton, California.

What is the warmest month in Fullerton?

The warmest month is August, with an average high-temperature of 83.5°F (28.6°C) and an average low-temperature of 65.5°F (18.6°C).

What is the least humid month in Fullerton?

The least humid month is November, with an average relative humidity of 51%.

What is the coldest month in Fullerton?

With an average high-temperature of 64°F (17.8°C) and an average low-temperature of 50.9°F (10.5°C), December is the coldest month.

What is the rainiest month in Fullerton?

December is the month with the most rainfall in Fullerton, California. Rain falls for 6.6 days and accumulates 1.54" (39mm) of precipitation.

What is the month with the shortest days in Fullerton?

December has the shortest days of the year in Fullerton, with an average of 9.9h of daylight.

What is the month with the least sunshine in Fullerton?

The month with the least sunshine in Fullerton, California, is December, with an average of 6.7h of sunshine.
Average temperature - Fullerton, CA
Average rainfall - Fullerton, CA
Average rainfall days - Fullerton, CA

The month with the highest number of rainy days is March (7.3 days).
The month with the lowest number of rainy days is June (1.5 days).

Average daylight / Average sunshine - Fullerton, CA

The month with the longest days is June (Average daylight: 14.4h).
The month with shortest days is December (Average daylight: 9.9h).

Months with most sunshine are July and August (Average sunshine: 12h).
The month with least sunshine is December (Average sunshine: 6.7h).

Average UV index - Fullerton, CA

Months with the highest UV index are June, July, August and September (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 4).