You think we get a lot of snow here in the Northern Plains, try Blue Canyon, California. Blue Canyon averages 240.8 inches of snow per year and is the snowiest recording station in the U.S.. Of course, it is also in the higher elevations. Number two on the list is low elevation Marquette, Michigan with 128.6 inches of snow. Other top 10 locations include #5 Caribou, Maine at 110.4 inches per year and #7 Lander, Wyoming with 102.5 inches per year. In contrast, the Sioux Falls area averages around 40 inches of snow per year.
February 2nd, 1905 marked the second coldest low for the Sioux City airport for the month of February. On this day, the mercury dropped to 30 degrees below zero. This was also the third coldest low ever recorded for Sioux City. The coldest low for Sioux City is 35 degrees below zero on January 12th, 1912 and the second coldest low bottomed out at 31 below on February 11th, 1899.
On February 3rd, 1947 the temperature dipped to -81 degrees at the recording station in Snag, in the Yukon Territory. This is the coldest temperature ever recorded in the Northern Hemisphere. A temperature of -96 degrees was recorded on January 7th, 1982 near Summit Lake in British Columbia. While the recording was likely accurate it was not official and, therefore, the "official" record is still 81 degrees below zero.
Very high winds combined with a brief period of heavy snow brought blizzard or near-blizzard conditions to most of Iowa over February 4th and 5th, 1984. A cold front moving down from the north was accompanied by a short initial "burst" of snow, leaving about an inch in only 15 to 30 minutes in many areas. Another 2 to 3 inches fell before the event was over. Thirty to 45 mph winds along and behind the front coupled with temperatures at or below zero to produce bitterly cold wind chills and poor visibilities.
Lake effect snows in the Great Lakes region can produce copius amounts of snow in a short period of time. On February 3rd through the 5th, 1972, a major lake effect snowstorm isolated Oswego, NY as 50 inches or more of snow fell in about 48 hours. It is very difficult, if not impossible to get these kind of snows in the plains. For example, Sioux City's snowiest month on record is January, 1982, where 29.1 inches fell. That is a long way from Oswego, New York's 50 plus inches in 48 hours.
The winter of 1916-1917 holds the record for the most snow received in Sioux City in a single winter season. That season, 72.8 inches of snow fell. The most snow that has fallen in Sioux City in a calendar year, from January 1st through December 31st, occurred more recently in 1983 when 64.7 inches fell. Ironically though, none of these years are in the top five wettest precipitation years for Sioux City.
The year 1936 has long been remembered as one of the hot, dry and dusty years of the "dirty thirties." In contrast, 1936 also started out extremely cold. The coldest month on record in Sioux City was February of 1936. For that entire month the average temperature was only 1.9 degrees above zero. During this month in 1936, four record low-highs and four record lows were set in Sioux City that stand to this day. In addition, the winter of 1935-1936 holds the record for the most heating degree days in Sioux City at 7,731.
February 8th, 1899 marked the coldest day on record for Sioux City. On this day, the average temperature for Sioux City was only 24 degrees below zero. The low for this day was a frigid 27 below, and the high was just 22 degrees below zero. Incidentally, these two temperatures hold the record low, and the record low-high for this date that stand to this day. On a side note, during this day in 1957 three inches of ice fell on Mt. Haleakala. What is so unusual about this ice storm is that this mountain is located in Hawaii.
On February 9th through 11th, 1988, widespread moderate to heavy snow fell across all of Iowa. The heaviest amounts were in a broad band that extended from northwest, through central, into east central and southeast Iowa. Amounts of 5 to nearly 10 inches were comon in these areas. The rest of the state received 1 to 3 inches. To have one snow event blanket the whole state is not real common.
A strong arctic cold front dropped south across Iowa during the early morning through mid-day hours on February 10th, 1995. Strong winds of 30 to 45 mph were common in northwest Iowa behind this front and Estherville reported a gust to 50 mph. Fortunately, there was no snow on the ground so ground blizzards and visibility were not a problem. However, the arctic air ushered in temperatures to near 0. These temperatures combined with the strong winds created wind chills of 30 to 65 degrees below zero.
On February 9th through 11th, 1981, a winter storm dumped 4 to 6 inches of snow over much of Iowa, with 2 to 3 inches common in the north. Visibility was at or near zero and the very strong winds and cold temperatures combined to create wind chills of 60 degrees below zero. Many major roads, including the interstates were closed. Schools were also closed, and several people died in car accidents or exposure.
February is not the coldest month on average for the Sioux City area, in fact, it comes in third place. Not surprising, January is the coldest month with a monthly average temperature of 17.7 degrees. December is the second coldest with a monthly average of 21.8 degrees. February is the third coldest at 23.6. However, February does hold the record for the coldest single month. In February 1936, the average temperature was just 1.9 degrees above zero.
On February 13th, 1993, residents of Iowa were cleaning up from a freezing rain event which lasted off and on for three days prior to this date. Shallow arctic air was located at the surface underneath warm air aloft. The ice caused some tree and power line damage over northwest Iowa. Power outages were reported in O'Brien and Emmet Counties. The power was out for several hours at both Primghar and Estherville. The ice caused significant problems as far as travel was concerned with several major accidents and hundreds of minor accidents. Interstate 80 was closed due to ice accumulation for a few hours.
Strong winds of up to 50 miles an hour and snowfall up to 14 inches combined to make life difficult across the tri-state area from February 14th through the 16th, 1979. Visibilities were reduced to near zero in many areas. Temperatures dipped to as low as -25 degrees. The strong winds created wind chills that approached 90 degrees below zero. Nearly all roads were closed across the tri-state area. Across northwest Iowa drifts piled to 10 to 12 feet high while in southwest Minnesota around 100 semis were stalled near Jackson and a freight train was brought to a halt. In southeast South Dakota some areas lost power as the strong winds took down power lines and snapped adjacent lines into one another.
On February 15th and 16th, 1990 portions of the Northern Plains were hit with a significant snow storm. The heavy snow developed in southwest South Dakota on the 15th and slowly spread eastward. Amounts of 3 to 6 inches were common across South Dakota although a narrow band of 10 to 12 accumulations stretched from the Pierre area to Huron. Six inches fell in Sioux Falls. The storm also dumped an 8 to 11 inch band into central Minnesota. Portions of Iowa were glazed with freezing rain, including the Des Moines area where over 250 car accidents were reported in a 3 hour period.
On February 16th, 1936, Sioux City was in the midst of an extreme cold spell. Record lows were set at Sioux City for three days in a row in mid-February 1936. They are 22 degrees below zero on the 14th, 20 below zero on the 15th, and finally 25 degrees below zero on the 16th. Another record low of 15 below zero was set a few days later on the 19th. Four record lows in one week is not common.
On February 17th and 18th, 1984, heavy wet snow, accompanied at times with thunder and lightning, fell throughout northeast Nebraska. Very heavy amounts in excess of 10 inches fell in an area from Sioux City westward. Twenty or more inches of snow was common throughout all of northeast Nebraska. Snow amounts included 24 inches at Verdigre and 22 inches at Norfolk. Twenty- four hour snowfall totals set records at many locations including Norfolk. Winds of 20 to 40 mph resulted in blowing and drifting snow making many roads impassable. The wet snow also resulted in scattered power outages.
A low-pressure system moved across Kansas, through northern Missouri and into Illinois on February 18th, 1991. As a result, heavy snow fell over extreme northwestern Iowa. Amounts were generally in the 3 to 6 inch range, with local amounts to near 9 inches. Estherville received 9 inches, while Spencer had 6. Most of the snow fell in only a 3 to 4 hour period during the morning.
On February 18th and 19th, 1984, heavy snow moved eastward from northeast Nebraska from the previous two days into northwest Iowa. While the snowline extended from the southwest corner all the way to the northeast, west central and northwest Iowa were the hardest hit. Strong winds of 20 to 40 mph contributed to the difficult traveling conditions brought by the storm and power outages due to fallen lines were common. Nearly a foot of snow fell at Sioux City and Akron reported 13 inches.
On February 20th and 21st, 1993 a copious amount of moisture was fed over a cold Arctic airmass across the Northern Plains producing widespread snowfall. The heaviest amounts were reported across northwest Iowa as a convective snow band dumped 12 to 16 inches from Sioux City northeastward to near Cherokee. Sioux City reported 15 inches with the storm. Unofficial reports in the Storm Lake area came in with 18 to 20 inches of new snow. Some areas received thunder with the snow and the convective nature led to tremendous snowfall rates. In some areas snow piled up at the rate of 3 to 4 inches an hour.
Snow also occurred across nearly all of South Dakota with the heaviest amounts in the southeast where 6 to 9 inches fell. The Sioux falls area came in with 6 inches of new snow.
On February 20th and 21st, 1976, a blizzard rolled eastward from Nebraska and into Iowa. Rain and thundershowers began on the evening of the 20th followed by strong winds in excess of 50 mph, heavy snow and falling temperatures. Blizzard conditions were reported in a 100 mile wide band from southwest through central and into northeast Iowa. Snow amounts of 8 to 12 inches were common. Highway travel was hazardous, if not impossible as roads became blocked. Numerous traffic accidents happened including one accident involving a Greyhound Bus. Many power and communications outages occurred which closed businesses and schools.
On February 21st and 22nd, 1993, a surface low pressure system intensified over the southern U.S. and passed to the south of Iowa. By the time the low was passing to the south, placing Iowa in the area of snow, very cold air aloft had settle over the state. The result was a snow that was very light and fluffy in texture. Snowfall amounts from this storm were only in the one to four inch range, but winds of 30 mph whipped the snow about easily. At times, blizzard conditions were reported, especially over the northern part of the state.
Severe weather is very unusual in the northern plains in February, but this kind of weather occurred in northern Iowa on February 23rd, 1977. A tornado touched down on a house in Mason City lifting the roof off and virtually destroying the house. Neighboring homes also received extensive roof damage. Shortly after this, a funnel cloud was spotted by a railroad crew.
On February 24th and 25th, 1994, an Alberta Clipper dropped southeast across the high plains and into the Ohio Valley. The storm was well organized and caused serious ground blizzard conditions across Iowa. Moisture was limited with this storm, but the entire state received a quick burst of two to four inch snows. The big problem with this system was the strong winds and cold temperatures that followed the snowfall. Winds shifted to the northwest and produced occasional gusts to 50 mph. The winds whipped the fluffy snow producing zero visibilities and drifts in excess of 10 feet in some locations.
On February 24th and 25th, 1993 the tri-state area in and around Sioux City was hit with a second snowstorm in five days. The light fluffy snow piled up to 5 to 10 inches in most areas. The totals from the two storms exceeded a foot across portions of northwest Iowa allowing the new snow to drift easily. Much of the snow fell in about eight hours.
At what temperature is it too warm to snow? An initial reaction to this question might be "when the temperature is above the melting point of 32 degrees". But, that is not the case. In fact, often snowstorms will begin with a surface temperature near 36 degrees. You may wonder why the snow doesn't melt in these warm temperatures. Well, to a degree it does.
For snow to survive in temperatures above freezing relative humidities must be below 100 percent. The reason for this is that as the snow falls into air that is not saturated a little melting of the flakes occurs. This water quickly evaporates and lowers the air's temperature and the temperature of the flake, thus retarding the melting process. As this process continues the air temperature continues to fall. In fact, sometimes rain will change over to snow because of this process. So, when is it too warm to snow? In rare cases the cold, relatively dry air from a thunderstorm has swept snowflakes to the surface with temperatures over 50 degrees!
Weather extremes are a way of life in the plains. For Sioux City, the snowiest February on record occurred in 1936 where 25 inches fell. The least snowiest February on record occurred in 1931 and 1946 where only a trace of snow fell. The temperature extremes are just as wide. In February of 1954, the average temperature was a very mild 37.7 degrees. The coldest February on record occurred in 1936 where the average temperature for the month was just 1.9 degrees.
Although no detailed records were kept this long ago, the winter season of 1856 through 1857 was apparently a very severe winter in the Sioux City area. A quote from a source is as follows: "A very cold and stormy winter with several large snowstorms. In Dakota County, Nebraska, the temperature did not get above freezing for 40 days and snow stood four feet deep on the level."
While many people start looking forward to spring as we approach March, March is the snowiest month on average for many locations in the northern plains. On average, Sioux City receives 7.7 inches of snow in March, while Sioux Falls receives 10.2 inches of snow.