This report describes the typical weather at the Jefferson City Memorial Airport (Jefferson City, Missouri, United States) weather station over the course of an average year. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Jefferson City, Missouri has a humid continental climate with hot summers and no dry season. The area within 25 mi of this station is covered by forests (96%).
Over the course of a year, the temperature typically varies from 22°F to 89°F and is rarely below 6°F or above 97°F.
The warm season lasts from May 27 to September 16 with an average daily high temperature above 78°F. The hottest day of the year is July 18, with an average high of 89°F and low of 70°F.
The cold season lasts from November 29 to February 23 with an average daily high temperature below 48°F. The coldest day of the year is January 11, with an average low of 22°F and high of 38°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 9:28 hours of daylight; the longest day is June 20 with 14:52 hours of daylight.
The earliest sunrise is at 5:43am on June 14 and the latest sunset is at 8:37pm on June 26. The latest sunrise is at 7:39am on November 3 and the earliest sunset is at 4:47pm on December 6.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 18% (mostly clear) to 62% (partly cloudy). The sky is cloudiest on January 25 and clearest on July 29. The clearer part of the year begins around May 24. The cloudier part of the year begins around November 6.
On July 29, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 52% of the time, and overcast or mostly cloudy 24% of the time.
On January 25, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 42% of the time, and clear or mostly clear 35% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around April 17, occurring in 44% of days. Precipitation is least likely around August 12, occurring in 32% of days.
Over the entire year, the most common forms of precipitation are light rain, thunderstorms, and light snow.
Light rain is the most severe precipitation observed during 33% of those days with precipitation. It is most likely around April 11, when it is observed during 19% of all days.
Thunderstorms are the most severe precipitation observed during 31% of those days with precipitation. They are most likely around June 5, when it is observed during 22% of all days.
Light snow is the most severe precipitation observed during 15% of those days with precipitation. It is most likely around January 13, when it is observed during 20% of all days.
During the warm season, which lasts from May 27 to September 16, there is a 35% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of thunderstorms (57% of days with precipitation have at worst thunderstorms), light rain (29%), and moderate rain (9%).
During the cold season, which lasts from November 29 to February 23, there is a 41% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light snow (40% of days with precipitation have at worst light snow), light rain (24%), moderate rain (8%), and drizzle (8%).
The likelihood of snow falling is highest around January 17, occurring in 25% of days. The season in which it is relatively likely for snow to fall spans from November 19 to March 27.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 44% (comfortable) to 94% (very humid) over the course of the year, rarely dropping below 25% (dry) and reaching as high as 100% (very humid).
The air is driest around April 9, at which time the relative humidity drops below 54% (mildly humid) three days out of four; it is most humid around August 24, exceeding 91% (very 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 year, the dew point typically varies from 15°F (dry) to 72°F (very muggy) and is rarely below -5°F (dry) or above 78°F (oppressive).
There are two periods in the year that are most comfortable: The first is between April 16 and June 4 and the second is between September 11 and October 24. The air feels neither too dry nor too muggy during these periods.
Over the course of the year typical wind speeds vary from 0 mph to 17 mph (calm to moderate breeze), rarely exceeding 23 mph (fresh breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around April 2, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around August 2, at which time the average daily maximum wind speed is 11 mph (gentle breeze).