This report describes the typical weather at the Hartsfield-Jackson Atlanta International Airport (Atlanta, Georgia, United States) weather station over the course of an average October. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Atlanta, Georgia has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by croplands (47%), forests (29%), and built-up areas (23%).
The month of October is characterized by falling daily high temperatures, with daily highs decreasing from 76°F to 68°F over the course of the month, exceeding 84°F or dropping below 57°F only one day in ten.
Over the course of October, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 59 minutes, implying an average day-over-day decrease of 1.9 minutes.
The shortest day of the month is October 31 with 10:50 hours of daylight; the longest day is October 1 with 11:49 hours of daylight.
The earliest sunrise is at 7:33am on October 1; the latest sunset is at 7:21pm on October 1; the latest sunrise is at 7:56am on October 31; the earliest sunset is at 6:46pm on October 31.
Daylight savings time is observed in 2012 but it neither starts nor ends in October, so the entire month is in daylight time.
The median cloud cover is 47% (partly cloudy) and does not vary substantially over the course of the month.
On October 16, a representative day, the sky is clear or mostly clear 47% of the time, partly cloudy 14% of the time, and mostly cloudy or overcast 38% of the time.
The average probability that some form of precipitation will be observed in a given day is 33%, with little variation over the course of the month.
Throughout October, the most common forms of precipitation are moderate rain, light rain, thunderstorms, and heavy rain.
Moderate rain is the most severe precipitation observed during 35% of those days with precipitation. It is most likely around October 28, when it is observed during 12% of all days.
Light rain is the most severe precipitation observed during 32% of those days with precipitation. It is most likely around October 30, when it is observed during 11% of all days.
Thunderstorms are the most severe precipitation observed during 15% of those days with precipitation. They are most likely around October 1, when it is observed during 7% of all days.
Heavy rain is the most severe precipitation observed during 11% of those days with precipitation. It is most likely around October 31, when it is observed during 4% of all days.
Either snow is exceptionally unlikely to fall at this location in October or this station does not reliably report precipitation types.
The relative humidity typically ranges from 46% (comfortable) to 89% (very humid) over the course of a typical October, rarely dropping below 26% (dry) and reaching as high as 100% (very humid).
The air is driest around October 24, at which time the relative humidity drops below 56% (mildly humid) three days out of four; it is most humid around October 1, rising above 83% (humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a typical October, the dew point typically varies from 41°F (dry) to 60°F (comfortable) and is rarely below 26°F (dry) or above 69°F (muggy).
The time of the month between October 1 and October 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of October typical wind speeds vary from 2 mph to 14 mph (light air to moderate breeze), rarely exceeding 20 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around October 2, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around October 23, at which time the average daily maximum wind speed is 13 mph (moderate breeze).