Average Weather in Atlanta Georgia, United States
In Atlanta, the temperature typically varies from 35°F to 89°F over the course of the year, and is rarely below 22°F or above 95°F.
The hot season lasts for 3.8 months, from May 24 to September 18, with an average daily high temperature above 81°F. The hottest day of the year is July 22, with an average high of 89°F and low of 72°F.
The cool season lasts for 2.9 months, from November 28 to February 25, with an average daily high temperature below 60°F. The coldest day of the year is January 23, with an average low of 35°F and high of 53°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
The length of the day in Atlanta varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 55 minutes of daylight; the longest day is June 21, with 14 hours, 24 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:26 AM on June 12, and the latest sunrise is 1 hour, 33 minutes later at 7:59 AM on November 4. The earliest sunset is at 5:28 PM on December 4, and the latest sunset is 3 hours, 23 minutes later at 8:52 PM on June 29.
Daylight saving time (DST) is observed in Atlanta during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
In Atlanta, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Atlanta begins around July 22 and lasts for 4.1 months, ending around November 25. On October 15, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 67% of the time, and overcast or mostly cloudy 33% of the time.
The cloudier part of the year begins around November 25 and lasts for 7.9 months, ending around July 22. On January 3, the cloudiest day of the year, the sky is overcast or mostly cloudy 54% of the time, and clear, mostly clear, or partly cloudy 46% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Atlanta varies throughout the year.
The wetter season lasts 3.8 months, from May 4 to August 30, with a greater than 32% chance of a given day being a wet day. The chance of a wet day peaks at 45% on July 9.
The drier season lasts 8.2 months, from August 30 to May 4. The smallest chance of a wet day is 19% on October 16.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 45% on July 9.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day in the year. Atlanta experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Atlanta. The most rain falls during the 31 days centered around March 1, with an average total accumulation of 4.6 inches.
The least rain falls around October 23, with and average total accumulation of 2.9 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Atlanta does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
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.
Atlanta experiences very significant seasonal variation in the perceived humidity.
The muggier period of the year lasts for 4.3 months, from May 21 to September 29, during which time the comfort level is muggy, oppressive, or miserable at least 22% of the time. The muggiest day of the year is July 25, with muggy conditions 86% of the time.
The least muggy day of the year is February 2, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
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 Atlanta experiences mildly seasonal variation over the course of the year.
The windier part of the year lasts for 6.8 months, from October 19 to May 12, with average wind speeds of more than 3.1 miles per hour. The windiest day of the year is March 8, with an average hourly wind speed of 3.9 miles per hour.
The calmer time of year lasts for 5.2 months, from May 12 to October 19. The calmest day of the year is August 5, with an average hourly wind speed of 2.3 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Atlanta varies throughout the year.
The wind is most often from the east for 3.8 months, from August 10 to December 3, with a peak percentage of 48% on September 8. The wind is most often from the west for 8.2 months, from December 3 to August 10, with a peak percentage of 43% on July 14.
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 experiences significant seasonal variation over the course of the year.
The brighter period of the year lasts for 4.6 months, from April 11 to August 29, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is June 6, with an average of 6.8 kWh.
The darker period of the year lasts for 2.8 months, from November 12 to February 6, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest day of the year is December 23, with an average of 2.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Atlanta are 33.749 deg latitude, -84.388 deg longitude, and 981 ft elevation.
The topography within 2 miles of Atlanta contains only modest variations in elevation, with a maximum elevation change of 180 feet, and an average elevation above sea level of 995 feet. Within 10 miles contains significant variations in elevation (495 feet). Within 50 miles contains large variations in elevation (2,014 feet).
The area within 2 miles of Atlanta is covered by artificial surfaces (100%), within 10 miles by artificial surfaces (83%) and trees (13%), and within 50 miles by trees (57%) and artificial surfaces (26%).
This report illustrates the typical weather in Atlanta, 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 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Atlanta.
For each station, the records are corrected for the elevation difference between that station and Atlanta 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 Atlanta is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Atlanta and a given station.
The stations contributing to this reconstruction are: Fulton County Airport-Brown Field (37%, 13 kilometers, west), Hartsfield-Jackson Atlanta International Airport (34%, 14 kilometers, south), and Dekalb-Peachtree Airport (28%, 16 kilometers, northeast).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports and weather stations are provided by AskGeo.com .