This report describes the typical weather at the Henry Post Army Airfield (Fort Sill/Lawton, Oklahoma, United States) weather station over the course of an average year. It is based on the historical records from 2004 to 2012. Earlier records are either unavailable or unreliable.
Fort Sill/Lawton, Oklahoma has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by grasslands (91%) and croplands (6%).
Over the course of a year, the temperature typically varies from 29°F to 97°F and is rarely below 20°F or above 104°F.
The warm season lasts from May 26 to September 8 with an average daily high temperature above 87°F. The hottest day of the year is July 30, with an average high of 97°F and low of 74°F.
The cold season lasts from November 23 to February 21 with an average daily high temperature below 59°F. The coldest day of the year is December 15, with an average low of 29°F and high of 50°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 9:51 hours of daylight; the longest day is June 20 with 14:29 hours of daylight.
The earliest sunrise is at 6:20am on June 15 and the latest sunset is at 8:51pm on June 25. The latest sunrise is at 7:57am on November 3 and the earliest sunset is at 5:22pm on December 4.
Daylight saving 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 40% (partly cloudy). The sky is cloudiest on February 29 and clearest on November 11. The clearer part of the year begins around June 12. The cloudier part of the year begins around January 16.
On November 11, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 59% of the time, and overcast or mostly cloudy 23% of the time.
On February 29, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 37% of the time, and clear or mostly clear 41% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around June 5, occurring in 38% of days. Precipitation is least likely around December 31, occurring in 18% of days.
Over the entire year, the most common forms of precipitation are light rain, thunderstorms, and moderate rain.
Light rain is the most severe precipitation observed during 30% of those days with precipitation. It is most likely around April 13, when it is observed during 11% of all days.
Thunderstorms are the most severe precipitation observed during 30% of those days with precipitation. They are most likely around May 22, when it is observed during 18% of all days.
Moderate rain is the most severe precipitation observed during 21% of those days with precipitation. It is most likely around November 12, when it is observed during 9% of all days.
During the warm season, which lasts from May 26 to September 8, there is a 33% 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 (40% of days with precipitation have at worst thunderstorms), light rain (29%), moderate rain (17%), and drizzle (11%).
During the cold season, which lasts from November 23 to February 21, there is a 21% 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 moderate rain (28% of days with precipitation have at worst moderate rain), light rain (27%), moderate snow (11%), and light snow (11%).
The likelihood of snow falling is highest around January 18, occurring in 8% of days.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 34% (comfortable) to 88% (very humid) over the course of the year, rarely dropping below 17% (dry) and reaching as high as 99% (very humid).
The air is driest around March 1, at which time the relative humidity drops below 42% (comfortable) three days out of four; it is most humid around October 16, exceeding 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 year, the dew point typically varies from 20°F (dry) to 70°F (muggy) and is rarely below 9°F (dry) or above 74°F (very muggy).
There are two periods in the year that are most comfortable: The first is between April 3 and May 27 and the second is between September 2 and October 27. The air feels neither too dry nor too muggy during these periods.
Over the course of the year typical wind speeds vary from 1 mph to 20 mph (calm to fresh breeze), rarely exceeding 27 mph (strong breeze).
The highest average wind speed of 13 mph (moderate breeze) occurs around March 27, at which time the average daily maximum wind speed is 20 mph (fresh breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around July 23, at which time the average daily maximum wind speed is 14 mph (moderate breeze).