Average Weather in June in Fullerton California, United States
Daily high temperatures increase by 6°F, from 76°F to 82°F, rarely falling below 70°F or exceeding 90°F.
Daily low temperatures increase by 4°F, from 60°F to 64°F, rarely falling below 56°F or exceeding 67°F.
For reference, on August 23, the hottest day of the year, temperatures in Fullerton typically range from 66°F to 86°F, while on December 25, the coldest day of the year, they range from 45°F to 67°F.
Average High and Low Temperature in June
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on June. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in June
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Sidi Smai’il, Morocco (5,947 miles away); Uitenhage, South Africa (10,354 miles); and Perth, Australia (9,361 miles) are the far-away foreign places with temperatures most similar to Fullerton (view comparison).
The month of June in Fullerton experiences gradually decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 18% to 10%. The lowest chance of overcast or mostly cloudy conditions is 10% on June 28.
The clearest day of the month is June 28, with clear, mostly clear, or partly cloudy conditions 90% of the time.
For reference, on February 20, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 43%, while on September 7, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 91%.
Cloud Cover Categories in June
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during June in Fullerton is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.4 inches or falling below -0.0 inches.
Average Monthly Rainfall in June
Over the course of June in Fullerton, the length of the day is essentially constant. The shortest day of the month is June 1, with 14 hours, 16 minutes of daylight and the longest day is June 21, with 14 hours, 25 minutes of daylight.
Hours of Daylight and Twilight in June
The earliest sunrise of the month in Fullerton is 5:40 AM on June 12 and the latest sunrise is 4 minutes later at 5:44 AM on June 30.
The earliest sunset is 7:57 PM on June 1 and the latest sunset is 9 minutes later at 8:06 PM on June 29.
Daylight saving time is observed in Fullerton during 2021, but it neither starts nor ends during June, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:41 AM and sets 14 hours, 25 minutes later, at 8:05 PM, while on December 21, the shortest day of the year, it rises at 6:53 AM and sets 9 hours, 54 minutes later, at 4:47 PM.
Sunrise & Sunset with Twilight in June
The figure below presents a compact representation of key lunar data for June 2021. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in June
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The chance that a given day will be muggy in Fullerton is essentially constant during June, remaining within 1% of 1% throughout.
For reference, on August 28, the muggiest day of the year, there are muggy conditions 8% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in June
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Fullerton is gradually decreasing during June, decreasing from 6.0 miles per hour to 5.5 miles per hour over the course of the month.
For reference, on December 31, the windiest day of the year, the daily average wind speed is 7.9 miles per hour, while on September 4, the calmest day of the year, the daily average wind speed is 5.1 miles per hour.
Average Wind Speed in June
The hourly average wind direction in Fullerton throughout June is predominantly from the west, with a peak proportion of 53% on June 1.
Wind Direction in June
Fullerton is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Fullerton is gradually increasing during June, rising by 3°F, from 63°F to 66°F, over the course of the month.
Average Water Temperature in June
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
Temperatures in Fullerton are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Time Spent in Various Temperature Bands and the Growing Season in June
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
The average accumulated growing degree days in Fullerton are rapidly increasing during June, increasing by 538°F, from 1,584°F to 2,122°F, over the course of the month.
Growing Degree Days in June
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy in Fullerton is essentially constant during June, remaining within 0.1 kWh of 8.4 kWh throughout.
The highest average daily incident shortwave solar energy during June is 8.5 kWh on June 22.
Average Daily Incident Shortwave Solar Energy in June
For the purposes of this report, the geographical coordinates of Fullerton are 33.870 deg latitude, -117.925 deg longitude, and 161 ft elevation.
The topography within 2 miles of Fullerton contains only modest variations in elevation, with a maximum elevation change of 361 feet and an average elevation above sea level of 185 feet. Within 10 miles contains only modest variations in elevation (1,647 feet). Within 50 miles contains very significant variations in elevation (10,062 feet).
The area within 2 miles of Fullerton is covered by artificial surfaces (100%), within 10 miles by artificial surfaces (89%), and within 50 miles by shrubs (37%) and water (30%).
This report illustrates the typical weather in Fullerton, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Fullerton.
For each station, the records are corrected for the elevation difference between that station and Fullerton according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Fullerton is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Fullerton and a given station.
The stations contributing to this reconstruction are: Fullerton Municipal Airport (79%, 5.0 kilometers, west); Fob Dwyer (10%, 21 kilometers, southeast); Chino Airport (5%, 29 kilometers, northeast); and Corona Municipal Airport (5%, 30 kilometers, east).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for airports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.