The best times to visit Fullerton for ideal weather are

February 26th to July 1st

or

October 1st to December 2nd

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.

 

 


Other Fullerton Travel Info

Weather in Fullerton

Temperature

Average temperatures in Fullerton vary somewhat. Considering humidity, temperatures feel very enjoyable all year with a very low chance of rain or snow throughout the year. The area is more temperate than most — in the 75th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Fullerton, the hottest months are August, September, and then July. See average monthly temperatures below. The warmest time of year is generally late August to early September where highs are regularly around 92°F (33.3°C) with temperatures rarely dropping below 68°F (20°C) at night.

Fullerton Temperatures (Fahrenheit)

Key
High
Average
Low

Fullerton Temperatures (Celsius)

Key
High
Average
Low

“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

Fullerton Perceived Temperature (F)

Key
High
Average
Low

Fullerton Perceived Temperature (C)

Key
High
Average
Low

 

Average Fullerton Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 72.3 57.5 46.1
Feb 71 57.9 47.8
Mar 75.1 61.7 51.8
Apr 76.3 63.7 54.1
May 78 66.6 58.5
Jun 80.4 69.3 62.2
Jul 85.2 73.3 65.8
Aug 88.2 75.2 66.5
Sep 88.6 74.5 65.1
Oct 83 69.3 58.9
Nov 76.6 62.2 51.3
Dec 68.8 56 45.8

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 22.4 14.2 7.8
Feb 21.7 14.4 8.8
Mar 23.9 16.5 11
Apr 24.6 17.6 12.3
May 25.6 19.2 14.7
Jun 26.9 20.7 16.8
Jul 29.6 22.9 18.8
Aug 31.2 24 19.2
Sep 31.4 23.6 18.4
Oct 28.3 20.7 14.9
Nov 24.8 16.8 10.7
Dec 20.4 13.3 7.7

 


 

Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Fullerton are June, August, and then July. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around late May to early June. For example, on the week of May 28th there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in late January with an average of 2 days of significant precipitation the week of January 22nd.

When can you find snow in Fullerton? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in Fullerton.

Key
Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Fullerton (in).

Key
Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 10% 0 1.8
Feb 13% 0 1.7
Mar 6% 0 0.8
Apr 5% 0 0.4
May 3% 0 0.2
Jun 0% 0 0
Jul 1% 0 0.1
Aug 0% 0 0
Sep 1% 0 0.3
Oct 4% 0 0.5
Nov 6% 0 0.7
Dec 15% 0 2.7

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 10 0 4.6
Feb 13 0 4.3
Mar 6 0 2
Apr 5 0 1
May 3 0 0.5
Jun 0 0 0
Jul 1 0 0.3
Aug 0 0 0
Sep 1 0 0.8
Oct 4 0 1.3
Nov 6 0 1.8
Dec 15 0 6.9

 

Humidity and Wind

Fullerton has some comfortably humid months, with slightly drier months on the other side of the year. The least humid month is January (42.1% relative humidity), and the most humid month is June (54.9%).

Wind in Fullerton is usually extremely calm. The windiest month is May, followed by April and June. May’s average wind speed of around 3.7 knots (4.2 MPH or 6.8 KPH) is considered “light air.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early to mid April where average top sustained speeds reach 9.8 knots, which is considered a gentle breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in Fullerton.

Key
Avg. Relative Humidity

Wind

The graph below shows wind speed (max and average) in knots.

Key
Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 2.3 Barely noticeable 7.7 Gentle breeze
Feb 2.7 Barely noticeable 8.4 Gentle breeze
Mar 3 Barely noticeable 8.7 Gentle breeze
Apr 3.5 Barely noticeable 9.4 Gentle breeze
May 3.7 Barely noticeable 8.9 Gentle breeze
Jun 3.5 Barely noticeable 8.3 Gentle breeze
Jul 3.3 Barely noticeable 8.1 Gentle breeze
Aug 2.9 Barely noticeable 7.9 Gentle breeze
Sep 2.6 Barely noticeable 7.8 Gentle breeze
Oct 2.5 Barely noticeable 7.8 Gentle breeze
Nov 2.2 Barely noticeable 7.5 Gentle breeze
Dec 2.2 Barely noticeable 7.4 Gentle breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 42.1%
Feb 49.7%
Mar 46.7%
Apr 45.1%
May 49.3%
Jun 54.9%
Jul 53.8%
Aug 49.9%
Sep 49.6%
Oct 48.2%
Nov 44.8%
Dec 50%

 

Is it Safe to Travel to Fullerton?

Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Dec 04, 2023.


 

The Busiest and Least Crowded Months

The busiest month for tourism in Fullerton, CA, US is July, followed by June and April. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Fullerton in November. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month

 

Most Popular Months to Visit

Key
Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is very reliable. Displayed data is calculated relative to the peak, so a score of 48.3 in November means 48.3% of the tourists vs. July.

 

 

Overall Fullerton Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderate. Highs range from 80.3°F (26.8°C) and 73.2°F (22.9°C) with warmer temperatures in the later months. Rain is rare with 1 to 2 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see the least precipitation with about 0 days of precipitation per month. June – August is the busiest season for tourism in Fullerton, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 91°F (32.8°C) and 73.6°F (23.1°C), which will feel very nice given the humidity and wind. It rains or snows a normal amount: 0 to 2 days per month. Tourism is fairly slow during these months due to the weather, so hotels may be lower priced.

Winter (December through February)

Weather is somewhat cool this time of year in Fullerton to be enjoyable for warm weather travelers. The average high during this season is between 74.3°F (23.5°C) and 67.4°F (19.7°C). On average, it rains or snows a fair amount: 3 to 5 times per month. These times of year are the slowest with tourists.

 

Best Times to Travel› the United States › Fullerton, CA, US