This report describes the historical weather record at the Missoula International Airport (Missoula, Montana, United States) during 1972. This station has records back to January 1948.
Missoula, Montana has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by forests (80%) and grasslands (20%)
Daylight saving time (DST) was observed at Missoula, Montana during 1972. There were two time changes during 1972:
1972 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 1972 February 29th falls on a Tuesday.
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 1972 they occurred on:
|Spring Equinox||Monday, 20 March 1972.|
|Summer Solstice||Wednesday, 21 June 1972.|
|Fall Equinox||Friday, 22 September 1972.|
|Winter Solstice||Thursday, 21 December 1972.|
The hottest day of 1972 was July 29, with a high temperature of 96°F. For reference, on that day the average high temperature is 86°F and the high temperature exceeds 95°F only one day in ten. The hottest month of 1972 was August with an average daily high temperature of 83°F.
Relative to the average, the hottest day was December 26. The high temperature that day was 54°F, compared to the average of 28°F, a difference of 26°F. In relative terms the warmest month was March, with an average high temperature of 50°F, compared to an typical value of 47°F.
The longest warm spell was from May 27 to June 11, constituting 16 consecutive days with warmer than average high temperatures. The month of March had the largest fraction of warmer than average days with 61% days with higher than average high temperatures.
The coldest day of 1972 was December 9, with a low temperature of -20°F. For reference, on that day the average low temperature is 19°F and the low temperature drops below 6°F only one day in ten. The coldest month of 1972 was December with an average daily low temperature of 13°F.
Relative to the average, the coldest day was December 9. The low temperature that day was -20°F, compared to the average of 19°F, a difference of 39°F. In relative terms the coldest month was December, with an average low temperature of 13°F, compared to an typical value of 18°F.
The longest cold spell was from December 2 to December 17, constituting 16 consecutive days with cooler than average low temperatures. The month of September had the largest fraction of cooler than average days with 77% days with lower than average low temperatures.
The longest freezing spell was from December 3 to December 17, constituting 15 consecutive days with temperatures strictly below freezing.
The clearest month of 1972 was August, with 77% of days being more clear than cloudy. The longest spell of clear weather was from August 24 to September 5, constituting 13 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1972 was January, with 45% of days being more cloudy than clear. The longest spell of cloudy weather was from January 9 to January 14, constituting 6 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 September 12. That day saw 0.622" of liquid (or liquid equivalent) precipitation, compared to a median value of 0.075". The month with the most precipitation was September, with 0.866", compared to a median value of 0.789".
As determined by quantitative measurements, the longest dry spell was from May 25 to June 16, constituting 23 consecutive days with no measured precipitation. The month with the largest fraction of dry days was August, 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 January, with 61% 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 1972 with the most precipitation observations was January 18. There were 8 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 106 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from August 3 to August 16, constituting 14 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was August, 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 January, with 81% 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 1972 with the largest number of those reports was December, with a total of 27 reports. The day with the largest number of those reports was January 20, with a total of 8 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 1972 was on September 24; the last was on April 29. The month of 1972 with the largest number of those reports was January, with a total of 82 reports. The day with the largest number of those reports was January 18, with a total of 8 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 1972 was July with an average daily low humidity of 27%, and the most humid month was February with an average daily low humidity of 67%.
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 1972, January had 31 dry days, no comfortable days, and no humid days; April had 30 dry days, no comfortable days, and no humid days; July had 22 dry days, 9 comfortable days, and no humid days; and October had 30 dry days, 1 comfortable day, and no humid days.
The highest sustained wind speed was 35 mph, occurring on March 6; the highest daily mean wind speed was 26 mph (January 26);
The windiest month was January, with an average wind speed of 9 mph. The least windy month was November, with an average wind speed of 5 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 1972 with the lowest average visibility was February 6, with an average visibility of 1.6 mi. The month with the lowest average visibility was January, with an average visibility of 11.3 mi. With an average visibility of 29.0 mi, the month of June had the highest average visibility.
This station did not reliably report the cloud ceiling during 1972.