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Welcome to the ask a scientist series from the National Weather Service Office in Las
Vegas, Nevada! In this installment, we will answer the question how often does it snow
in Las Vegas? When most people think of Las Vegas, they
think of a sunny, hot city in the Mojave Desert. In reality this is not the case! Las Vegas
does have 4 distinct seasons and we do experience winter, just not to the extreme that Chicago
or New York does. Even though palm trees do grow here (although
not naturally), Las Vegas is located at the same latitude as Oklahoma and North Carolina
– places that people do associate with having four distinct seasons. However, these states
receive much more precipitation than Las Vegas does during the year. Even though these places
are wetter, it is not the primary reason that they see snow more frequently than Las Vegas.
During the winter, cold air drains south from Canada and spills south and east of the Rocky
Mountains much more frequently than it does to the west of the Rockies. The Rocky Mountains
act as a barrier for the cold air to cross and as a result make it difficult for Arctic
air to move into the Southwestern United States. The lack of a sufficiently cold air mass is
the primary reason that snow is not common in Las Vegas even though we get precipitation
during the colder months. Las Vegas sits in a valley that slopes downward
from west to east. Elevations range from around 3300 feet above sea level in Summerlin on
the far west end to nearly 1600 feet on the far southeast end near Lake Las Vegas. The
Strip sits on average around 2100 feet in elevation. Typically, the coldest storm system
of the winter in this area will bring snow levels down to around 3000 feet. This is low
enough to allow for snow in the higher western edges of the Las Vegas Valley each year but
not over the center of the valley where our official long term climate station is located
at McCarran International Airport on the south end of The Strip.
The most favorable weather pattern for snow to fall in Las Vegas takes place when the
main storm track sets up to bring storms south along the coast and across southern California
and Arctic air can drain south from Canada into the southwestern United States. As long
as these storms have sufficient moisture with them and the depth of the cold air is significant
enough, precipitation will be able to fall as snow in Las Vegas. Having the rare combination
of a cold enough air mass and abundant moisture makes accumulating snow in Las Vegas even
harder to come by. Often, the colder storm systems have little in the way of moisture
while the storm systems that are accompanied by more moisture often lack enough cold air
to work with. Even though this storm track sets up a few times each winter, it rarely
has the right combination of ingredients to produce snow in Las Vegas.
In summary, the climatology of snow in Las Vegas can be summed up as follows. Snow falls
somewhere in the Las Vegas Valley each year. Snow has fallen in about two-thirds of the
years at the official climate station at McCarran International Airport. Measurable snow has
fallen in about 25 percent of the years at McCarran International Airport. On average,
measurable snow falls about once every 4 or 5 years at McCarran. Measurable snow falls
about every 2 to 3 years in the higher parts of the Las Vegas Valley such as Summerlin.
Snow is most common in January. Earliest snow ever was on November 15, 1964 when 3 inches
fell. Latest snow ever was on March 14, 1975. Measurable snow has fallen in every month
from November through March. Although official climate records for Las
Vegas start in 1937, two of the greatest snowstorms ever known in the Las Vegas Valley took place
back in the early days when Las Vegas was a little frontier town. In 1909, newspaper
and volunteer weather reports document a snowstorm on December 21st that dropped 10 to 15 inches
of snow in the Las Vegas Valley with 13 inches measured on Fremont Street by railroad depot
employees. In January 1932, from the 10th through the 12th, a storm dropped as much
as 12 inches of snow in Las Vegas. Since official records started in 1937, 3
months stand out the most for snow in Las Vegas. January 1949 leads all other months
for snow with 16.7 inches. More snow fell this month in Las Vegas then in Chicago that
entire winter season – their total was only 14.7 inches! This is the only time a month
has had 3 separate storms that have produced measurable snow in Las Vegas. Las Vegas saw
its biggest snowstorm ever in official records from the 9th through the 13th with 9.7 inches.
A record 13 consecutive days had a least a trace of snow on the ground. The combination
of the snow and cold crippled transportation and caused substantial losses in tourism.
January 1974 ranks as the second snowiest month ever with 13.4 inches. A total of 4
inches fell on New Year’s Day while another storm dropped a 24 hour record of 9.4 inches
from the 4th through the 5th. January 1979 had two measurable snowstorms, the later which
lasted into February 1st brought 7.8 inches of snow with it, most of which fell on January
31st. Snow fell continuously on January 31st for 23 hours and 31 minutes totaling a calendar
day record of 7.1 inches which was enough to close all Clark County schools as well
as UNLV. December 2008 ranks as the most recent month
in which significant snow has fallen in the Las Vegas Valley. Two separate storm systems
brought accumulating snow to the Las Vegas Valley, however, the heaviest snow fell in
different parts of the valley in both storms. The first storm from December 15th through
the 16th was a more elevation dependent storm and produced the heaviest snow on the west
side of the valley with as much as 5 inches in far northwest Las Vegas. On December 17th,
a storm produced heavy snow over the south end of the Las Vegas Valley. As much as 10
inches of snow fell in far southeast Henderson with 1 to 2 inches on the south end of The
Strip. In this later storm the heaviest snow fell in an unusual manor largely due to the
track of the storm and a greater presence of colder air in the south end of the valley.
Many areas in the middle of the Las Vegas Valley saw no accumulation of snow in this
later event! Thanks for watching this presentation! Visit
our website at weather.gov/lasvegas for more information on snow in Las Vegas.