This report describes the historical weather record at the Henry Post Army Airfield (Fort Sill/Lawton, Oklahoma, United States) during 1974. This station has records back to December 1947.
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%)
Daylight saving time (DST) was observed at Fort Sill/Lawton, Oklahoma during 1974. There were two time changes during 1974:
1974 was not a leap year, so it has 365 days and no February 29th. The first leap year before 1974 was 1972 and the first after was 1976.
The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 1974 they occurred on:
|Spring Equinox||Thursday, 21 March 1974.|
|Summer Solstice||Friday, 21 June 1974.|
|Fall Equinox||Monday, 23 September 1974.|
|Winter Solstice||Sunday, 22 December 1974.|
The hottest day of 1974 was July 22, with a high temperature of 111°F. For reference, on that day the average high temperature is 98°F and the high temperature exceeds 105°F only one day in ten. The hottest month of 1974 was July with an average daily high temperature of 101°F.
Relative to the average, the hottest day was February 1. The high temperature that day was 76°F, compared to the average of 52°F, a difference of 24°F. In relative terms the warmest month was July, with an average high temperature of 101°F, compared to an typical value of 98°F.
The longest warm spell was from July 17 to July 30, constituting 14 consecutive days with warmer than average high temperatures. The month of July had the largest fraction of warmer than average days with 87% days with higher than average high temperatures.
The coldest day of 1974 was January 12, with a low temperature of 12°F. For reference, on that day the average low temperature is 28°F and the low temperature drops below 19°F only one day in ten. The coldest month of 1974 was January with an average daily low temperature of 28°F.
Relative to the average, the coldest day was March 21. The low temperature that day was 25°F, compared to the average of 46°F, a difference of 20°F. In relative terms the coldest month was September, with an average low temperature of 60°F, compared to an typical value of 63°F.
The longest cold spell was from January 1 to January 14, constituting 14 consecutive days with cooler than average low temperatures. The month of September had the largest fraction of cooler than average days with 70% days with lower than average low temperatures.
The clearest month of 1974 was February, with 54% of days being more clear than cloudy. The longest spell of clear weather was from January 31 to February 5, constituting 6 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1974 was August, with 61% of days being more cloudy than clear. The longest spell of cloudy weather was from September 15 to September 26, constituting 12 consecutive days that were cloudier than they were clear.
This station provides hourly reports of significant weather events at and around the station, but does not report the quantity of precipitation at the station itself. This is common for weather stations located outside of the United States, and for a small subset of stations in the United States that are located at lesser used and smaller airports.
This station reports when significant weather events (including precipitation) are visually observed at or near the station. Such events do not always correspond to measured quantities of liquid equivalent precipitation, such as when the event is near by not at the station, or in the case of solid precipitation that does not melt in the collection basin.
The day in 1974 with the most precipitation observations was September 24. There were 22 hourly weather reports that day (out of a maximum of 24) in which some form of precipitation was observated at or near the station. The month with the most precipitation observations was September, with 93 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from January 23 to February 6, constituting 15 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was July, with 84% of days reporting no observed precipitation at all.
The month with the largest fraction of days with at least some observed precipitation was September, with 50% of days reporting some observed precipitation.
In this section we consider only those weather reports that indicate liquid precipitation. For the purposes of this analysis, we include thunderstorms even though some thunderstorms are not accompanied by liquid precipitation.
The month of 1974 with the largest number of those reports was September, with a total of 93 reports. The day with the largest number of those reports was September 24, with a total of 22 reports.
This station reports when snow is observed falling but does not report the quantity of snow that has fallen or the depth of snow on the ground.
In this section we consider hourly weather reports that contain an observation of falling snow. These reports do not necessarily correspond to accumulation.
The first reported snow fall in 1974 was on November 29; the last was on March 23. The month of 1974 with the largest number of those reports was January, with a total of 12 reports. The day with the largest number of those reports was November 29, with a total of 9 reports.
Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.
When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of 1974 was July with an average daily low humidity of 24%, and the most humid month was October with an average daily low humidity of 51%.
But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.
Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.
Generally speaking, dew points below 50°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50°F to 68°F are fairly comfortable to most people, and dew points above 68°F are increasingly uncomfortable, becoming oppressive around 77°F.
To take some examples, and basing our categorization on the daily high dew point in 1974, January had 30 dry days, 1 comfortable day, and no humid days; April had 15 dry days, 12 comfortable days, and 3 humid days; July had no dry days, 16 comfortable days, and 15 humid days; and October had 2 dry days, 27 comfortable days, and 2 humid days.
The highest sustained wind speed was 39 mph, occurring on April 20; the highest daily mean wind speed was 21 mph (March 23); and the highest wind gust speed was 49 mph (April 20).
The windiest month was April, with an average wind speed of 12 mph. The least windy month was August, with an average wind speed of 7 mph.
Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.
The day of 1974 with the lowest average visibility was January 14, with an average visibility of 1.7 mi. The month with the lowest average visibility was October, with an average visibility of 15.0 mi. With an average visibility of 22.5 mi, the month of June had the highest average visibility.
The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.
The day of 1974 with the lowest average cloud ceiling was January 29, with an average cloud ceiling of 49'. The month with the lowest average cloud ceiling was September, with an average cloud ceiling of 6097'. The month of July has the highest average cloud ceiling, with an average cloud ceiling of 20772'.