Historical Weather For 1964 in Los Angeles, California, USA

Location

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%)

Calendar

Daylight saving time (DST) was observed at Los Angeles, California during 1964. There were two time changes during 1964:

  • DST started on Sunday April 26, 1964 at 3:00 am, from PST (GMT-8) to PDT (GMT-7).
  • DST ended on Sunday October 25, 1964 at 1:00 am, from PDT (GMT-7) to PST (GMT-8).

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.

Temperature

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.

Temperature

The daily low (blue) and high (red) temperature during 1964 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile). The bar at the top of the graph is red where both the daily high and low are above average, blue where they are both below average, and white otherwise.

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.

Hourly Temperature Bands

The full year of hourly temperature reports with the days of the year on the horizontal and the hours of the day on the vertical. The hourly temperature measurement is color coded into meaningful temperature bands: frigid is purple (below 15°F), freezing is blue (15°F to 32°F), cold is dark green (32°F to 50°F), cool is light green (50°F to 65°F), comfortable is yellow (65°F to 75°F), warm is light red (75°F to 85°F), hot is medium red (85°F to 100°F), sweltering is dark red (above 100°F), and missing data is pink.

Clouds

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.

Cloud Coverage

The fraction of time spent in each of the five sky cover categories over the course of 1964 on a daily basis. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data. The bar at the top of the graph is gray if the sky was cloudy or mostly cloudy for more than half the day, blue if it is clear or mostly clear for more than half the day, and blue-gray otherwise.

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.

Hourly Cloud Coverage

The full year of hourly cloud coverage reports with the days of the year on the horizontal and the hours of the day on the vertical. The sky cover is color coded: from most blue to most gray, the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

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.

Liquid Equivalent Quantity

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.

Precipitation Quantity

The daily measured quantity of liquid (or liquid equivalent in the case of solid precipitation) precipitation over the course of 1964, with the median non-zero quantity (thick gray line) and 10th, 25th, 75th, and 90th non-zero percentiles (shaded areas). The bar at the top of the graph is green if any precipitation was measured that day and white otherwise.

Present Weather Reports

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.

Precipitation Reports

The daily number of hourly observed precipitation reports during 1964, color coded according to precipitation type, and stacked in order of severity. From the bottom up, the categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); and drizzle (lightest green). Not all categories are necessarily present in this particular graph. The faint shaded areas indicate climate normals. The bar at the top of the graph is green if any precipitation was observed that day and white otherwise.

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.

Hourly Weather Reports

The full year of hourly present weather reports with the days of the year on the horizontal and the hours of the day on the vertical. The color-coded categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); drizzle (lightest green); freezing rain and sleet (light and dark cyan); snow grains (lightest blue); hail (red); fog (gray); and haze (brownish gray).

Snow

Either snow is exceptionally rare at this location or this station did not reliably report it during 1964.

Humidity

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.

Humidity

The daily low (brown) and high (blue) relative humidity during 1964 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Dew 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.

Dew Point

The daily low (blue) and high (red) dew point during 1964 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

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.

Wind Speed

The daily low and high wind speed (light gray area) and the maximum daily wind gust speed (tiny blue dashes).

Visibility

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.

Visibility

The daily average visibility, depicted as gray bars encroaching down from the top of the graph.

Cloud Ceiling

This station did not reliably report the cloud ceiling during 1964.