This report describes the historical weather record at the Louisville International Airport (Louisville, Kentucky, United States) during 1963. This station has records back to January 1948.
Louisville, Kentucky 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 (76%), croplands (14%), and built-up areas (8%)
Daylight saving time (DST) was observed at Louisville, Kentucky during 1963. There were two time changes during 1963:
1963 was not a leap year, so it has 365 days and no February 29th. The first leap year before 1963 was 1960 and the first after was 1964.
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 1963 they occurred on:
|Spring Equinox||Thursday, 21 March 1963.|
|Summer Solstice||Saturday, 22 June 1963.|
|Fall Equinox||Monday, 23 September 1963.|
|Winter Solstice||Sunday, 22 December 1963.|
The hottest day of 1963 was August 3, with a high temperature of 94°F. For reference, on that day the average high temperature is 87°F and the high temperature exceeds 94°F only one day in ten. The hottest month of 1963 was July with an average daily high temperature of 84°F.
Relative to the average, the hottest day was April 1. The high temperature that day was 85°F, compared to the average of 63°F, a difference of 22°F. In relative terms the warmest month was October, with an average high temperature of 78°F, compared to an typical value of 68°F.
The longest warm spell was from October 1 to October 29, constituting 29 consecutive days with warmer than average high temperatures. The month of October had the largest fraction of warmer than average days with 94% days with higher than average high temperatures.
The coldest day of 1963 was January 24, with a low temperature of -15°F. For reference, on that day the average low temperature is 26°F and the low temperature drops below 11°F only one day in ten. The coldest month of 1963 was January with an average daily low temperature of 17°F.
Relative to the average, the coldest day was January 24. The low temperature that day was -15°F, compared to the average of 26°F, a difference of 41°F. In relative terms the coldest month was December, with an average low temperature of 19°F, compared to an typical value of 31°F.
The longest cold spell was from June 29 to July 18, constituting 20 consecutive days with cooler than average low temperatures. The month of December had the largest fraction of cooler than average days with 87% days with lower than average low temperatures.
The longest freezing spell was from December 13 to December 24, constituting 12 consecutive days with temperatures strictly below freezing.
The clearest month of 1963 was October, with 87% of days being more clear than cloudy. The longest spell of clear weather was from September 30 to October 24, constituting 25 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1963 was January, with 61% of days being more cloudy than clear. The longest spell of cloudy weather was from April 25 to May 1, constituting 7 consecutive days that were cloudier than they were clear.
This station reports both the quantity of liquid precipitation and categorical observations of precipitation (e.g., moderate rain, or heavy snow). Both are subject to erroneous reports, but the former is particularly prone to false reports, especially ones indicating an excessive quantity of precipitation. Please bear this in mind when reading the extrema reported in this section.
The day with the largest quantity of precipitation was March 16. That day saw 2.720" of liquid (or liquid equivalent) precipitation, compared to a median value of 0.160". The month with the most precipitation was March, with 9.059", compared to a median value of 4.018".
As determined by quantitative measurements, the longest dry spell was from September 13 to September 29, constituting 17 consecutive days with no measured precipitation. The month with the largest fraction of dry days was October, with 94% of days reporting no measured precipitation at all.
The month with the largest fraction of days with at least some measured precipitation was March, with 45% of days reporting some measured precipitation.
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 1963 with the most precipitation observations was February 10. There were 21 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 135 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from October 13 to October 27, constituting 15 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was October, with 90% 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 64% 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 1963 with the largest number of those reports was March, with a total of 128 reports. The day with the largest number of those reports was February 10, with a total of 21 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 1963 was on November 13; the last was on March 6. The month of 1963 with the largest number of those reports was December, with a total of 74 reports. The day with the largest number of those reports was December 23, with a total of 17 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 1963 was October with an average daily low humidity of 35%, and the most humid month was July with an average daily low humidity of 55%.
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 1963, January had 29 dry days, 2 comfortable days, and no humid days; April had 14 dry days, 15 comfortable days, and 1 humid day; July had no dry days, 7 comfortable days, and 24 humid days; and October had 6 dry days, 25 comfortable days, and no humid days.
The highest sustained wind speed was 35 mph, occurring on June 10; the highest daily mean wind speed was 18 mph (March 20);
The windiest month was March, with an average wind speed of 10 mph. The least windy month was October, with an average wind speed of 4 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 1963 with the lowest average visibility was January 6, with an average visibility of 1.5 mi. The month with the lowest average visibility was September, with an average visibility of 7.6 mi. With an average visibility of 10.4 mi, the month of April had the highest average visibility.
This station did not reliably report the cloud ceiling during 1963.