This report describes the historical weather record at the Los Angeles International Airport (Los Angeles, California, United States) during 1964. This station has records back to December 1947.
Los Angeles, California has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by oceans and seas (43%), built-up areas (40%), shrublands (11%), and forests (5%)
Daylight saving time (DST) was observed at Los Angeles, California during 1964. There were two time changes during 1964:
1964 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 1964 February 29th falls on a Saturday.
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 1964 they occurred on:
|Spring Equinox||Friday, 20 March 1964.|
|Summer Solstice||Sunday, 21 June 1964.|
|Fall Equinox||Wednesday, 23 September 1964.|
|Winter Solstice||Monday, 21 December 1964.|
The hottest day of 1964 was October 20, with a high temperature of 93°F. For reference, on that day the average high temperature is 72°F and the high temperature exceeds 81°F only one day in ten. The hottest month of 1964 was August with an average daily high temperature of 74°F.
Relative to the average, the hottest day was April 14. The high temperature that day was 91°F, compared to the average of 66°F, a difference of 25°F. In relative terms the warmest month was February, with an average high temperature of 67°F, compared to an typical value of 65°F.
The longest warm spell was from February 16 to February 24, constituting 9 consecutive days with warmer than average high temperatures. The month of February had the largest fraction of warmer than average days with 62% days with higher than average high temperatures.
The coldest day of 1964 was November 16, with a low temperature of 39°F. For reference, on that day the average low temperature is 54°F and the low temperature drops below 49°F only one day in ten. The coldest month of 1964 was February with an average daily low temperature of 46°F.
Relative to the average, the coldest day was November 16. The low temperature that day was 39°F, compared to the average of 54°F, a difference of 15°F. In relative terms the coldest month was May, with an average low temperature of 53°F, compared to an typical value of 58°F.
The longest cold spell was from April 23 to July 26, constituting 95 consecutive days with cooler than average low temperatures. The month of May had the largest fraction of cooler than average days with 100% days with lower than average low temperatures.
The clearest month of 1964 was February, with 90% of days being more clear than cloudy. The longest spell of clear weather was from June 27 to July 17, constituting 21 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1964 was June, with 50% of days being more cloudy than clear. The longest spell of cloudy weather was from December 16 to December 25, constituting 10 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 December 27. That day saw 0.724" of liquid (or liquid equivalent) precipitation, compared to a median value of 0.226". The month with the most precipitation was December, with 1.984", compared to a median value of 1.539".
As determined by quantitative measurements, the longest dry spell was from June 10 to October 27, constituting 140 consecutive days with no measured precipitation. The months February, July, August, and September were completely without measured precipitation.
The month with the largest fraction of days with at least some measured precipitation was December, with 23% 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 1964 with the most precipitation observations was December 20. There were 20 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 December, with 86 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 March 2, constituting 40 consecutive days with no observed precipitation. The month February was completely without observed precipitation.
The month with the largest fraction of days with at least some observed precipitation was December, with 32% of days reporting some observed precipitation.
Either snow is exceptionally rare at this location or this station did not reliably report it during 1964.
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 1964 was February with an average daily low humidity of 24%, and the most humid month was June with an average daily low humidity of 63%.
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 1964, January had 15 dry days, 16 comfortable days, and no humid days; April had 14 dry days, 16 comfortable days, and no humid days; July had no dry days, 31 comfortable days, and no humid days; and October had no dry days, 31 comfortable days, and no humid days.
The highest sustained wind speed was 40 mph, occurring on March 16; the highest daily mean wind speed was 20 mph (March 16);
The windiest month was March, with an average wind speed of 11 mph. The least windy month was December, with an average wind speed of 8 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 1964 with the lowest average visibility was October 10, with an average visibility of 0.8 mi. The month with the lowest average visibility was October, with an average visibility of 6.8 mi. With an average visibility of 16.0 mi, the month of February had the highest average visibility.
This station did not reliably report the cloud ceiling during 1964.