Fullerton, California, enjoys a mild Mediterranean climate, making it a desirable place to live or visit any time of the year.
Summers in Fullerton are short, warm, arid, and generally clear, with temperatures typically ranging from 45°F to 86°F.
The city rarely experiences temperatures below 39°F or above 95°F, ensuring comfortable weather throughout the year.
During winter, the weather becomes cooler and partly cloudy, with the city experiencing long, yet mild winters.
Fullerton receives an average of 14 inches of rain annually.
For those interested in sunshine, summer months offer the most daylight, with up to 12 hours of direct sunlight in July and August, making it perfect for outdoor activities and exploring the city.
Whether you’re planning a visit or considering a move, understanding the climate of Fullerton can help you make the most of your time in this charming California city.
For more detailed information, you can check historical weather data and monthly climate averages at timeanddate.com or other similar resources.
Average Temperature in Fullerton, California
In Fullerton, California, temperatures can vary greatly throughout the year.
The hottest month is usually August, with an average high of 85°F and a low of 66°F.
The coldest month is December, where high temperatures average around 67°F and lows dip to about 45°F.
The table below shows the average high and low temperatures for each month:
| Month | Average High (°F) | Average Low (°F) |
|---|---|---|
| January | 68 | 45 |
| February | 69 | 47 |
| March | 70 | 49 |
| April | 74 | 52 |
| May | 75 | 56 |
| June | 80 | 61 |
| July | 85 | 65 |
| August | 85 | 66 |
| September | 83 | 63 |
| October | 78 | 57 |
| November | 72 | 50 |
| December | 67 | 45 |
The warmest months are July and August, while the cooler months span from November to March.
In the cool season, temperatures remain below 71°F from November 25 to March 21.
Fullerton experiences a mild climate, making it a comfortable place year-round.
Average Precipitation in Fullerton, California
Fullerton experiences very little rainfall throughout the year, making it a dry region. Snow is almost nonexistent, contributing to a mild winter climate.
Average Rainfall in Fullerton, California
Rainfall in Fullerton is minimal, with the wettest month being December. During this month, the city receives about 2.6 inches of rain.
The driest months are typically April through November, with very little precipitation.
Overall, Fullerton experiences around 13 inches of precipitation annually.
This low level of rainfall reflects the area’s dry climate, typical of Southern California.
Rainy days are relatively few and mainly concentrated in the winter months, ensuring dry weather most of the year.
Average Snow in Fullerton, California
Snowfall in Fullerton is almost unheard of. Due to the city’s low elevation and Southern California location, temperatures rarely drop low enough to produce snow.
Winter temperatures remain mild, ensuring that snow and ice are not a concern.
Local residents and visitors alike can enjoy a snow-free experience, even during the colder months of the year.
Snow-related activities and conditions are not part of the local climate in Fullerton.
Average Sun in Fullerton, California
Fullerton, California, enjoys plenty of sunshine throughout the year. The city experiences high levels of daily solar energy, with long sunny days in the summer.
Average Daily Shortwave Solar Energy in Fullerton, California
Fullerton receives abundant shortwave solar energy throughout the year.
During the summer months, the city gets the most sunlight, peaking around June, July, and August.
June has about 11.9 hours of direct sunlight, July has about 12 hours, and August also records 12 hours of sunshine per day.
In winter, daylight hours are shorter, and the sun’s intensity diminishes.
However, the city still enjoys mild and sunny days.
Even in December, one of the colder months, Fullerton has an average high of 68°F and about 6 hours of sunshine daily.
The UV index in the summer can be quite high, making sun protection important.
With less intense sunlight in the winter, the UV index drops but remains at moderate levels.
This consistent sunlight makes Fullerton an attractive place for outdoor activities year-round.
Average Humidity in Fullerton, California
Fullerton, California, experiences varying levels of humidity throughout the year. The relative humidity tends to fluctuate depending on the season.
Monthly Humidity Levels:
- March: Highest relative humidity at 66.55%
- November: Lowest relative humidity at 57.52%
These humidity levels give a good idea of how moist the air is at different times of the year.
Dew Point:
Dew point is a measure of moisture in the air. Higher dew points indicate more humidity. In Fullerton, the dew point varies with temperature changes across seasons.
- Summer: Dew points can be higher, contributing to a muggy feel.
- Winter: Lower dew points result in drier air.
Average Wind in Fullerton, California
Fullerton, California, experiences gentle breezes throughout the year.
The average wind speed is about 5 mph. This mild wind keeps the air fresh and comfortable most of the time.
Wind speeds do not vary much between seasons.
Even in the windiest month, the wind remains gentle, making outdoor activities pleasant.
Fullerton’s geography contributes to this calm wind pattern. Located inland and shielded by surrounding areas, it avoids extreme wind conditions.
In some months, residents might notice slightly stronger gusts. However, compared to other parts of the country, the winds here remain mild and consistent.
Average Air Quality in Fullerton, California
Fullerton, California, often enjoys good air quality, especially during certain times of the year. The Air Quality Index (AQI) measures pollutants like particulate matter (PM2.5, PM10), ozone (O3), and nitrogen dioxide (NO2).
Most of the time, the AQI in Fullerton ranges from good to moderate.
For real-time updates and forecasts, residents and visitors can rely on platforms like IQAir or WeatherBug.
It’s important to note the seasonal variations in air quality.
During summer months, ozone levels can rise due to higher temperatures and increased sunlight.
Winter months might bring elevated particulate matter due to lower atmospheric pressure and increased use of heating.
Common Air Quality Indicators:
- PM2.5 and PM10: Fine and coarse particles can affect respiratory health.
- Ozone (O3): This can cause respiratory issues and other health problems.
- Nitrogen Dioxide (NO2): Usually from vehicles, it can aggravate lung conditions.
Key Metrics:
- AQI Categories:
- 0-50: Good
- 51-100: Moderate
- 101-150: Unhealthy for sensitive groups
- 151-200: Unhealthy
- 201-300: Very Unhealthy
- 301-500: Hazardous
Additional Considerations:
- Visibility: Poor air quality can reduce visibility, impacting driving safety.
- Pressure: Lower atmospheric pressure in winter can trap pollutants closer to the ground, worsening air quality.
Topography of Fullerton, California
Fullerton is located in Orange County, California. The city lies about 11 miles northeast of the Pacific Ocean. This proximity influences its terrain and elevation.
Elevation: Fullerton’s average elevation is 259 feet (79 meters) above sea level. This moderate elevation contributes to its Mediterranean climate.
Terrain: The city features a variety of landscapes, including rolling hills, flat lands, and some urban areas. The hills offer scenic views and are popular for outdoor activities.
Geographical Features:
- Coyote Hills: These hills are among the prominent features in Fullerton. They provide hiking trails and natural habitats.
- Fullerton Creek: This creek runs through parts of the city, contributing to its natural beauty.
- Parks and Green Spaces: Fullerton is home to several parks that enhance its landscape.
Click here to explore the region in more detail using the interactive Fullerton topographic map.
Extreme Weather Events that Occur in Fullerton, California
Fullerton, California, experiences various extreme weather events. Here are some notable ones:
Fullerton sees intense heat waves, especially during summer.
Temperatures can soar above 100°F.
These high temperatures can last for several days, making it crucial for residents to stay hydrated and cool.
Droughts
Droughts are common in Fullerton and can last for months.
Limited rainfall and high temperatures contribute to dry conditions.
Water restrictions often follow to conserve the scarce resource.
Santa Ana winds are strong, dry winds that blow through Southern California, including Fullerton.
These winds can reach speeds of 40 to 60 mph, increasing the risk of wildfires.
They usually occur in the fall and winter.
While mostly dry, Fullerton can experience heavy rains leading to flooding.
This usually happens during winter storms.
The city has areas prone to flash floods, and residents are often warned to stay cautious.
Hail
Hail can accompany thunderstorms in Fullerton. Though not frequent, hailstones can be as large as an inch in diameter.
These storms can cause significant damage to property and vehicles.
Earthquakes
Although not a weather event, earthquakes are part of the extreme conditions faced.
Fullerton is near several fault lines, making it susceptible to seismic activity.
Residents are advised to have an emergency plan in place.
Best Time of the Year to Visit Fullerton, California
Fullerton, California offers pleasant weather throughout the year, but the ideal time to visit may depend on personal preferences regarding temperature and activities. Here’s a closer look at what to expect during each season.
What is Fullerton, California Like in Spring
Spring in Fullerton runs from March to May.
Temperatures are comfortable, ranging from 60°F to 75°F.
Rainfall is moderate, making it a good time for outdoor activities without the intense heat.
Days are sunny, and the blooming flowers make local parks beautiful.
This season is ideal for touring the city or attending local events.
Tourists will find fewer crowds, which can make for a more relaxing visit.
What is Fullerton, California Like in Summer
Summer spans from June to August, and it is the warmest season.
Temperatures typically range from 75°F to 88°F.
The skies are mostly clear, and sunshine is abundant with long daylight hours.
Rainfall is minimal, which is perfect for outdoor pools and barbecues.
This is a peak tourist season, so expect more crowded attractions and higher hotel rates.
Beaches are nearby, providing a great escape from the heat.
What is Fullerton, California Like in Fall
Fall lasts from September to November.
Temperatures cool down, ranging from 65°F to 80°F.
This season experiences less rain, providing consistent, enjoyable weather for visitors.
The city becomes less crowded as schools are back in session.
Events such as local festivals and market days become common.
It’s a great time to explore cultural attractions and enjoy outdoor restaurants.
The mild temperatures and clear skies make it a favorite for many visitors.
What is Fullerton, California Like in Winter
Winter in Fullerton runs from December through February.
Temperatures range from 45°F to 65°F. While it’s the coolest season, it’s still quite mild compared to other parts of the country.
Rainfall is higher during these months, averaging around 3 to 5 days of rain per month.
Snow is rare.
Winter is a great time for visiting museums or indoor activities.
It’s also less busy, making hotel rates more affordable.