Siouxland Weather History and Trivia

October 1 -

The average date of the first freeze in Sioux City is October 7th. The earliest first freeze on record occurred on September 13th, 1902 and the latest first freeze on record occurred on November 2nd, 1924.

October 2 -

Methane (also known as swamp gas), along with carbon monoxide, is a major greenhouse gas. Because of population growth and changes in the planet's land use patterns, by the year 2000 atmospheric methane is expected to be six times as high as it was in the year 1800. Although a greenhouse gas that could, in theory, lead to an increase in global temperatures, the higher methane levels' actual effect on the earth's climate remains under debate.

October 3 -

One of the very first computers dedicated to atmospheric science performed about 1000 additions a second. Today's larger, more powerful machines clip out over a billion additions per second and that's not nearly enough to approach duplicating the incredible complexity of the atmosphere or satisfy atmospheric researchers.

October 4 -

Something that is an important consideration for meteorologists across much of the central plains is something called the upslope effect. The upslope effect is caused by the gentle rise in elevations across the central plains from the Mississippi River to the Rocky Mountains. As air flows up this gentle rise the lifting of the air leads to cooling. This cooling can contribute to extensive cloud cover, fog, and precipitation, especially in the winter months.

A more pronounced upslope effect can occur along the Rockies and the Black Hills. If winds force air directly into these mountains the air will be lifted along the earthen boundaries. This dramatic lifting will often lead to the development of thunderstorms in the summer, or significant snows in the winter along the mountains that the surrounding lower elevations may not receive.

October 5 -

On October 5th, 1971, a severe thunderstorm cut a path of damage about 3 miles long and 2 miles wide from about 4 miles north of Sutherland and on northeastward in O'Brien County. Strong winds and up to golfball size hail was reported. Three farms sustained considerable damage to machinery and buildings. Two of the farm houses were damaged. There was considerable crop damage, but no injuries to persons or livestock.

October 6 -

On October 6th, 1994, a surface low pressure system formed over the Rockies and advanced across the plains into South Dakota. A cold front bowed southeast and south of the low across central South Dakota and into eastern Nebraska. With the unstable weather situation, a line of thunderstorms developed during the mid to late afternoon hours of the 6th. The storms quickly became severe as they moved into western Iowa. Monona and Crawford Counties were especially hard hit. There were numerous reports of golfball size hail and one storm produced baseball size hail over the Ute area of Monona County. Baseball size hail also fell a short time later east of Soldier. As the storms moved east, high winds were the major problem causing some roof damage.

October 7 -

Approximately twelve percent of our nation's electricity comes from renewable resources: hydroelectric, biomass, municipal waste, wind, solar, and geothermal. Hydropower is by far the largest contributor. However, most of the country's major rivers are already being utilized for hydropower, therefore, additional hydroelectric power resources are minimal. Use of wind and solar power has quite a bit of potential as an increased energy source.

October 8 -

Late on October 8th and into the 9th of 1970 the area was hit with an early season snowstorm. The heavy snows affected portions of western Iowa and western Minnesota. Amounts of up to 7 inches were recorded in northwest Iowa. The heavy, wet snow snapped many tree branches and downed power lines. Sioux city recorded their heaviest snow for so early in the season.

The heavy snows also affected portions of southeast South Dakota. Vermillion received 6 inches of snow and that is the largest amount ever recorded there for so early in the season. The 5 inches that fell in Sioux Falls is the earliest significant snow on record for that city. The snow was very wet and heavy, but melted quickly over the next several days.

October 9 -

On October 9th, 1973, thunderstorms raced into the tri-state area. Strong thunderstorm winds downed trees, power lines and several farm buildings across Plymouth, Sioux, O'Brien, and Osceola counties in northwest Iowa. Two small tornadoes also developed across northwest Iowa that evening. The first was near Hinton (in Plymouth county) and the second was near Sheldon (in O'Brien county). Fortunately, neither tornado did much damage.

Heavy rains and hail pounded extreme eastern South Dakota during the late evening hours. 3.79 inches of rain fell in a 2 hour period at the Sioux Falls airport setting a new rainfall intensity record for a two hour period in Sioux Falls. The 4.54 inches that fell that day is the second highest amount on record for a 24 hour period in Sioux Falls.

October 10 -

October 10th historically has been a slow weather day around the tri-state area. This was not the case in the Black Hills of South Dakota on October 8th through 10th, 1982. During this three-day period, record amounts of snow piled up in the northern Black Hills. Not only was the storm a record breaker because it came so early in the season, it was a record snowfall producer for anytime of year.

Amounts of three to six feet were common across the northern hills. On October 9th, 1982 thirty-two inches of snow buried Lead. Lead's three day storm total from the 8th through the 10th was an astounding 55.3 inches. To put the 55.3 inch storm total in perspective, the tri-state area around Sioux City averages about 32 to 35 inches of snow in an entire winter.

October 11 -

What city in the United States has the most days with precipitation? Well, not by coincidence Hilo, Hawaii, which is the wettest city in the country with an annual average precipitation of 128.00 inches, also has the most rainy days at 277. Number 2 on the list is Quillayute (pronounced key-a-ute), WA with 210 days. By contrast, Sioux City averages 99 days a year with precipitation.

October 12 -

Living in the mid-latitudes as we do allows us to experience a wide range of weather phenomena and temperature extremes. The range of recorded temperature extremes in the United States is 214 degrees Fahrenheit. The hottest temperature on record in the U.S. is 134 degrees and the coldest is -80 degrees. The recorded temperature range for the entire planet is an amazing 263 degrees. With the hottest temperature on record being 136 degrees and the coldest a bone chilling -127 degrees.

Sioux City has a range of 146 degrees between its highest and lowest temperatures, with 111 degrees being the hottest and - 35 degrees the coldest. In contrast some tropical islands have never seen their temperature vary by more than 30 or 40 degrees.

October 13 -

If you like lots of the sun then, not surprisingly, the best place in the United States for you is in the desert southwest. The sunniest city in the U.S. is Yuma, Arizona which sees 90% of the yearly possible sunshine. Second on the list is Las Vegas, Nevada which receives around 85% of the possible sunshine. Las Vegas also holds the distinction of being the least humid city in the country with an annual average relative humidity of just 30.5%. In contrast, most of the northern plains see around 50 to 60% of the possible yearly sunshine.

October 14 -

On October 14th and 15th, 1966, a very damaging early season snowstorm produced 4 inches of heavy, wet snow in the Sioux City area. Coupled with winds gusting to 40 miles an hour, this snowstorm caused extensive damage to trees, power and telephone lines. Clean-up of the broken trees and limbs took several weeks.

October 15 -

Good news for folks looking for a cleaner more environmentally safe energy source. Over the last two decades, the cost of solar-generated electricity dropped around 1,000 percent. One industry group predicts that solar power could be cost competitive with conventional electrical utilities by the turn of the century. Of course, solar power also has the tremendous advantage of being a renewable resource.

October 16 -

On October 16th, 1980, a squall line packing damaging winds swept across the area. The line of thunderstorms developed around 2 pm and moved east and northeast at over 50 miles an hour. A large portion of southeast South Dakota was belted with winds of 50 to 70 miles an hour. Yankton reported winds of 60 to 70 miles an hour while Sioux Falls was hit with a 62 mile an hour gust. Considerable damage was done in southeast South Dakota to trees, farm structures, and small buildings. Damage estimates were 100 to 200 thousand dollars. West of Sioux City, Knox County Nebraska also received heavy damage from straight line winds and a tornado. The twister caused extensive damage to a farm house 12 miles north of Bloomfield.

By late afternoon the thunderstorms were roaring through southwest Minnesota with 50 to 70 mile an hour winds. Numerous outbuildings and many trees were downed or damaged. In Redwood county two combines and a 24 foot travel trailer were tipped over and damaged. Northwest Iowa was spared the strongest winds from this squall line.

October 17 -

Wind power has the potential to become a fairly significant energy source across portions of the United States. The possibility of wind generating electricity was brought about with the combination of advancing technology and the old idea of windmills. Apparently, windmills were first used extensively in the Middle East all the way back in the 11th century. Around 200 years later they became established in Europe. In the 1400's the Dutch were using wind power to drain swamps and marshes and before the start of this century, the Danes were using wind to generate some 40 megawatts of electrical power. In the future in this country wind power may generate up 10 percent of the electricity in some areas.

October 18 -

Annual weather related losses in the United States are estimated to be as high as $34.5 billion dollars. New technologies are helping to prevent losses that could be significantly higher than this. Weather satellites save the country money. According to the National Oceanic and Atmospheric Administration (NOAA), the use of information supplied by weather satellites saves key industries such as agriculture, construction, shipping, fishing, utilities, and aviation more than $5 billion dollars a year.

October 19 -

On October 19th, 1982, thunderstorms and hail preceded snow as a cold front moved through the region. Hail, ranging from pea sized to one inch in diameter, fell in and around Cleghorn, in Cherokee County. The hail fell for about 10 minutes damaging corn and soybean fields. The scale at the farmers' co-op elevator accumulated 3,000 pounds of hail. Later that day, a snowstorm dropped 3 to 12 inches of wet snow over southeast South Dakota and up to 8 inches in southwest Minnesota and northwest Iowa. A foot of snow fell in Newcastle of Dixon County. Numerous trees still laden with foliage and power lines were downed across the area. The snow was convective in nature as lightning flashed in some areas. Winds up to 40 miles an hour in concert with the heavy snow proved too much for some structures. Radio and TV transmitters were knocked down in Sioux Falls. In Vermillion, the weight of the snow collapsed the fiber glass roof panel on the covered stadium at the University of South Dakota.

October 20 -

What nation has the worst weather on earth? If you consider the range of possibilities (heat, cold, floods, drought, tornadoes, tropical storms, etc.) the United States happens to come up number one. We receive this dubious distinction through a combination of factors. Some of the important influences include being on a large land mass in the mid-latitudes which allows for a greater range of temperatures in the interior. This leads to clashes of vastly different air masses as cold, dry air moves into the country from the north and warm, moist air settles in from the south. Also, the Gulf of Mexico is a significant and, often, easily accessible moisture source that fuels inclement weather across the eastern 2/3rds of the country.

These are only a couple of the factors that contribute to our wild weather in the U.S..

October 21 -

Have you ever heard the weather saying "When the wind is out of the east, 'tis good for neither man nor beast?"

Well, there is some truth to the old saying. Typically, if one is experiencing a northeast or east wind it means that an area of low pressure...which often produces inclement nearby.

October 22 -

Trees happen to be one of nature's best fighters of air pollution. It is reported that one acre of trees can filter a massive 13 tons of dust and gaseous pollutants from the air per year.

October 23 -

On a nice clear day you may have heard someone say they could see "forever". In actuality, the limit of visibility in a perfectly clear atmosphere, meaning a minimum of dirt or pollution, is around 200 miles.

October 24 -

Some old folklore goes "If the rooster crows at night, he's trying to say rain's in sight."

There is actually some merit to the old saying. Basically, a rooster's feathers act as insulation, so the changes in air pressure, temperature, and humidity that precede inclement weather may make a rooster uncomfortable and cause him to crow.

October 25 -

In every month of the year, the warmest temperature on record in the U.S. is 100 degrees or higher. In nine out of the 12 months the record low in the U.S. is below zero. The record U.S. record low in June is +2, in July it's +10, and in August it's +5 degrees.

October 26 -

For all you fishing fans out there here's a little weather folklore for you. There is some truth to the saying "when fish break water and bite eagerly, expect rain." The connection with the weather is this: when the barometric pressure starts to fall (this often precedes precipitation), gas bubbles in the water clinging to decaying matter expand and cause the matter to rise to the surface. This moves the whole feeding chain to the water's surface.

October 27 -

The driest month on record for Sioux City occurred in October 1952 and 1958. For these months, only a trace of precipitation fell. The wettest October on record occurred in 1979 where 5.30 inches of liquid precipitation was recorded.

October 28 -

Weatherwise, October can be one of the more pleasant months in the Sioux City area. The normal high for the month of October in Sioux City is a comfortable 64 degrees while the average low is 40. In addition, the sun shines an average of 63 percent of the time. Severe weather is usually not too frequent in October, both in terms of convective weather and winter storms.

October 29 -

October 29th, 1925 is the coldest day on record in the month of October in Sioux City. The temperature dipped to a cold 5 degrees above zero that morning and still stands as the earliest day in the winter season that Sioux City reached 5 degrees.

October 30 -

On October 30th, 1979, an intense storm system produced major rainfall in the Sioux City area. On this date, 4.42 inches of rain fell at the Sioux City airport, which stands as the greatest rainfall for the month of October in a 24 hour period. Further west in north central Nebraska, cold air caused that area to receive nearly 10 inches of snow.

October 31 -

A strong winter storm belted portions of the Northern Plains from October 30th through November 1st, 1991. Arctic air flowed into the area following the passage of a cold front. Later on, intense low pressure moved northeast along the frontal boundary. Snow began falling over the tri-state area on the evening of the 30th, with the heaviest falling during the afternoon and night of the 31st. Eight to 15 inches fell in northwest Iowa with Estherville receiving 15 inches. Sioux Falls accumulated 11.2 inches in a 24 hour period from October 31st to November 1st.

Further south, ice was the main problem. The Omaha/Council Bluffs area had over an inch of freezing rain causing the cancellation of Halloween. All told, utility damage was estimated near 63 million dollars in Iowa alone. The ice and snow did not melt easily as sub-freezing temperatures lingered over the area for a week. is the U.S. government's official web portal to all federal, state and local government web resources and services.