Average Weather in April in Fullerton California, United States
Daily high temperatures increase by 3°F, from 72°F to 75°F, rarely falling below 63°F or exceeding 87°F.
Daily low temperatures increase by 4°F, from 52°F to 56°F, rarely falling below 47°F or exceeding 60°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 April
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on April. 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 April
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 April in Fullerton experiences gradually decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 30% to 24%.
The clearest day of the month is April 30, with clear, mostly clear, or partly cloudy conditions 76% 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 April
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Fullerton, the chance of a wet day over the course of April is decreasing, starting the month at 10% and ending it at 5%.
For reference, the year's highest daily chance of a wet day is 20% on February 19, and its lowest chance is 0% on July 2.
Probability of Precipitation in April
The average sliding 31-day rainfall during April in Fullerton is decreasing, starting the month at 1.1 inches, when it rarely exceeds 2.9 inches, and ending the month at 0.4 inches, when it rarely exceeds 1.1 inches or falls below -0.0 inches.
Average Monthly Rainfall in April
Over the course of April in Fullerton, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 57 minutes, implying an average daily increase of 1 minute, 59 seconds, and weekly increase of 13 minutes, 51 seconds.
The shortest day of the month is April 1, with 12 hours, 34 minutes of daylight and the longest day is April 30, with 13 hours, 31 minutes of daylight.
Hours of Daylight and Twilight in April
The latest sunrise of the month in Fullerton is 6:38 AM on April 1 and the earliest sunrise is 35 minutes earlier at 6:03 AM on April 30.
The earliest sunset is 7:12 PM on April 1 and the latest sunset is 22 minutes later at 7:34 PM on April 30.
Daylight saving time is observed in Fullerton during 2018, but it neither starts nor ends during April, 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 6:52 AM and sets 9 hours, 54 minutes later, at 4:46 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in April
The chance that a given day will be muggy in Fullerton is essentially constant during April, remaining around 0% 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 April
The average hourly wind speed in Fullerton is essentially constant during April, remaining within 0.2 miles per hour of 6.8 miles per hour throughout.
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 April
Wind Direction in April
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 essentially constant during April, remaining within 1°F of 60°F throughout.
Average Water Temperature in April
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 April
The average accumulated growing degree days in Fullerton are increasing during April, increasing by 358°F, from 739°F to 1,097°F, over the course of the month.
Growing Degree Days in April
The average daily incident shortwave solar energy in Fullerton is increasing during April, rising by 1.1 kWh, from 6.5 kWh to 7.6 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in April
For the purposes of this report, the geographical coordinates of Fullerton are 33.870 deg latitude, -117.925 deg longitude, and 180 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 year round, 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 (78%, 5.0 kilometers, west); Fob Dwyer (11%, 21 kilometers, southeast); Chino Airport (6%, 29 kilometers, northeast); and Corona Municipal Airport (6%, 30 kilometers, east).
Time zones for aiports and weather stations are provided by AskGeo.com .