This report describes the historical weather record at the Little Rock Air Force Base (Jacksonville, Arkansas, United States) during 1968. This station has records back to January 1956.
Jacksonville, Arkansas has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by forests (46%), grasslands (25%), croplands (23%), built-up areas (4%), and lakes and rivers (3%)
Daylight saving time (DST) was observed at Jacksonville, Arkansas during 1968. There were two time changes during 1968:
1968 was a leap year and thus has 366 days rather than the normal 365. Leap years occur every fourth year and the extra day is always February 29th. In 1968 February 29th falls on a Thursday.
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 1968 they occurred on:
|Spring Equinox||Wednesday, 20 March 1968.|
|Summer Solstice||Friday, 21 June 1968.|
|Fall Equinox||Sunday, 22 September 1968.|
|Winter Solstice||Saturday, 21 December 1968.|
The hottest day of 1968 was July 27, with a high temperature of 97°F. For reference, on that day the average high temperature is 93°F and the high temperature exceeds 100°F only one day in ten. The hottest month of 1968 was July with an average daily high temperature of 90°F.
Relative to the average, the hottest day was January 29. The high temperature that day was 67°F, compared to the average of 50°F, a difference of 17°F. In relative terms the warmest month was June, with an average high temperature of 87°F, compared to an typical value of 88°F.
The longest warm spell was from January 26 to February 7, constituting 13 consecutive days with warmer than average high temperatures. The month of June had the largest fraction of warmer than average days with 57% days with higher than average high temperatures.
The coldest day of 1968 was January 7, with a low temperature of 9°F. For reference, on that day the average low temperature is 31°F and the low temperature drops below 18°F only one day in ten. The coldest month of 1968 was February with an average daily low temperature of 29°F.
Relative to the average, the coldest day was January 7. The low temperature that day was 9°F, compared to the average of 31°F, a difference of 22°F. In relative terms the coldest month was February, with an average low temperature of 29°F, compared to an typical value of 35°F.
The longest cold spell was from January 4 to January 18, constituting 15 consecutive days with cooler than average low temperatures. The month of February had the largest fraction of cooler than average days with 86% days with lower than average low temperatures.
The clearest month of 1968 was October, with 74% of days being more clear than cloudy. The longest spell of clear weather was from October 14 to October 23, constituting 10 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1968 was January, with 84% of days being more cloudy than clear. The longest spell of cloudy weather was from January 1 to January 15, constituting 15 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 1968 with the most precipitation observations was November 27. There were 23 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 January, with 140 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from October 18 to November 3, constituting 17 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was October, with 81% of days reporting no observed precipitation at all.
The month with the largest fraction of days with at least some observed precipitation was January, with 55% 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 1968 with the largest number of those reports was January, with a total of 120 reports. The day with the largest number of those reports was November 27, with a total of 23 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 1968 was on January 1; the last was on March 22. The month of 1968 with the largest number of those reports was February, with a total of 27 reports. The day with the largest number of those reports was February 21, 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 1968 was February with an average daily low humidity of 33%, and the most humid month was January with an average daily low humidity of 54%.
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 1968, January had 24 dry days, 7 comfortable days, and no humid days; April had 9 dry days, 21 comfortable days, and no humid days; July had no dry days, 4 comfortable days, and 27 humid days; and October had 9 dry days, 19 comfortable days, and 3 humid days.
The highest sustained wind speed was 34 mph, occurring on March 11; the highest daily mean wind speed was 18 mph (March 11);
The windiest month was March, with an average wind speed of 7 mph. The least windy month was July, with an average wind speed of 3 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 1968 with the lowest average visibility was January 31, with an average visibility of 3.0 mi. The month with the lowest average visibility was January, with an average visibility of 10.3 mi. With an average visibility of 16.2 mi, the month of February 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 1968 with the lowest average cloud ceiling was January 2, with an average cloud ceiling of 377'. The month with the lowest average cloud ceiling was December, with an average cloud ceiling of 4338'. The month of July has the highest average cloud ceiling, with an average cloud ceiling of 7960'.