This report describes the historical weather record at the Joplin Regional Airport (Joplin, Missouri, United States) during 1975. This station has records back to January 1948.
Joplin, Missouri 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 (60%), grasslands (32%), croplands (5%), and built-up areas (2%)
Daylight saving time (DST) was observed at Joplin, Missouri during 1975. There were two time changes during 1975:
1975 was not a leap year, so it has 365 days and no February 29th. The first leap year before 1975 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 1975 they occurred on:
|Spring Equinox||Friday, 21 March 1975.|
|Summer Solstice||Sunday, 22 June 1975.|
|Fall Equinox||Tuesday, 23 September 1975.|
|Winter Solstice||Monday, 22 December 1975.|
The hottest day of 1975 was July 6, with a high temperature of 98°F. For reference, on that day the average high temperature is 89°F and the high temperature exceeds 96°F only one day in ten. The hottest month of 1975 was July with an average daily high temperature of 90°F.
Relative to the average, the hottest day was December 14. The high temperature that day was 70°F, compared to the average of 46°F, a difference of 24°F. In relative terms the warmest month was January, with an average high temperature of 47°F, compared to an typical value of 43°F.
The longest warm spell was from October 30 to November 10, constituting 12 consecutive days with warmer than average high temperatures. The month of January had the largest fraction of warmer than average days with 68% days with higher than average high temperatures.
The coldest day of 1975 was December 18, with a low temperature of 5°F. For reference, on that day the average low temperature is 27°F and the low temperature drops below 13°F only one day in ten. The coldest month of 1975 was February with an average daily low temperature of 27°F.
Relative to the average, the coldest day was March 14. The low temperature that day was 8°F, compared to the average of 38°F, a difference of 30°F. In relative terms the coldest month was March, with an average low temperature of 33°F, compared to an typical value of 39°F.
The longest cold spell was from February 22 to March 6, constituting 13 consecutive days with cooler than average low temperatures. The month of March had the largest fraction of cooler than average days with 77% days with lower than average low temperatures.
The clearest month of 1975 was October, with 58% of days being more clear than cloudy. The longest spell of clear weather was from October 1 to October 10, constituting 10 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1975 was February, with 71% of days being more cloudy than clear. The longest spell of cloudy weather was from January 28 to February 7, constituting 11 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 1975 with the most precipitation observations was February 4. 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 February, with 141 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from October 2 to October 14, constituting 13 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was October, 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 February, with 54% 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 1975 with the largest number of those reports was February, with a total of 79 reports. The day with the largest number of those reports was February 4, with a total of 23 reports.
This station reports both when snow is observed to be falling and the measured depth of the snow on the ground. Both are subject to erroneous reports, but the latter is significantly less reliable. Please bear this in mind when reading this section.
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 1975 was on August 5; the last was on April 2. The month of 1975 with the largest number of those reports was February, with a total of 62 reports. The day with the largest number of those reports was February 23, with a total of 20 reports.
Snow depth on the ground is an optional and inconsistently reported part of standard weather reports. It is rarely reported more often than every six hours, it is often skipped, it is often reported erroneously, and a snow depth of zero is normally not distinguished from a missing report. These issues (particularly the last one) make it hard to collect statistics on snow depth with any confidence. To overcome this issue, we base our statistics on only those reports with present non-zero measurements of snow depth. Reports that fail to mention snow that is present, and reports that do not report snow depth because there is no snow on the ground are excluded because they cannot be distinguished from one another.
The first reported accumulation in 1975 was on November 26. The last day of the snow season with snow reported on the ground was March 15. The day with the deepest snow depth was March 10, with an average snow depth of 7.9" over the course of the day. The longest stretch of time during which there was always snow on the ground was from March 9 to March 16 (8 consecutive days).
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 1975 was April with an average daily low humidity of 38%, and the most humid month was December with an average daily low humidity of 59%.
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 1975, January had 27 dry days, 4 comfortable days, and no humid days; April had 18 dry days, 12 comfortable days, and no humid days; July had no dry days, 7 comfortable days, and 24 humid days; and October had 10 dry days, 20 comfortable days, and 1 humid day.
The highest sustained wind speed was 40 mph, occurring on June 17; the highest daily mean wind speed was 23 mph (April 23); and the highest wind gust speed was 48 mph (April 8).
The windiest month was April, with an average wind speed of 12 mph. The least windy month was September, with an average wind speed of 6 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 1975 with the lowest average visibility was December 12, with an average visibility of 1.0 mi. The month with the lowest average visibility was February, with an average visibility of 9.1 mi. With an average visibility of 13.5 mi, the month of October 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 1975 with the lowest average cloud ceiling was July 1, with an average cloud ceiling of 271'. The month with the lowest average cloud ceiling was December, with an average cloud ceiling of 6456'. The month of July has the highest average cloud ceiling, with an average cloud ceiling of 14688'.