ASk A Researcher

June 2014

Extreme Weather Patterns - North Dakota Has It All

Michael Noone was born in Melbourne, Australia, and grew up in Alaska. In North Dakota, he received his B.S. and M.S. in Ecology, and eventually gainful employment. Since 2002, he has worked for the North Dakota State Water Commission as a Planner and Natural Resource Economist. He has also served as an adjunct professor of Geographic Information Systems at Bismarck State College since 2009. In this article, he discusses North Dakota’s climate today and historical trends.

Q: What is North Dakota’s climate like?

Since settlement days, North Dakota has experienced extreme weather patterns such as during the “Dirty Thirties,” the extended wet cycle that led to the rise of Devils Lake, and the disastrous Red River Valley flood of 1997. In the last five years, the state has experienced record floods in 2009 and 2011, and an exceedingly dry year in 2012. Prior to European settlement, geological records indicate that the region saw periods of wet and dry that may have been more intense and lasted longer than those experienced in the last 130 years.

It is not uncommon for the state to experience extreme drought in one place, and severe flooding in another, sometimes on the same day. North Dakota is located in a region of central North America that bridges the divide between “too wet” and “too dry.” The 100th Meridian line of longitude roughly splits the state in half. East of this line, there is generally more precipitation in the form of snow and rain than there is the uptake of water by plants and evaporation. West of the 100th Meridian, water loss generally exceeds precipitation. Recent fluctuations in climate have shown that this artificial boundary between wet and dry shifts slightly east or west depending upon larger climatic patterns. Geological evidence indicates that this boundary can shift even more dramatically. This range of climates varies not only geographically, east to west, but over time as well.

Q: What are the extremes and statistics for North Dakota’s climate?

• Highest temperature: 121 degrees, Steele on July 6, 1936.
• Lowest temperature: 60 degrees below zero, Parshall, February 15, 1936.
• The average first day of frost occurs in mid-September in northern parts of the state.
• The average last day of frost occurs in mid to late May.
• North Dakota receives a higher percentage of possible sunshine and more hours of sunshine annually than any other state along the Canadian border. On an annual basis, the state receives 58 to 62 percent of total possible sunshine.
• July is the sunniest month, when approximately three-quarters of possible sunshine is recorded. July and August will record about twice as many sunshine days, than during any other month of the year.
• Average yearly rainfall ranges from 24 inches in the southeastern portion of the state, to 14 inches in the far west.
• The largest rainfall event in a nearly 24-hour period was 10.05 inches, recorded in June 2000 in Gilby.
• When compared to the period from 1907-1992, average annual precipitation has increased during the “wet cycle” period (1993-2011) by approximately 29% in Fargo, 28% in Bismarck, and 11% in Dickinson.

Q: Describe drought in North Dakota

Drought has often been a defining aspect of climate in North Dakota since settlement days, from the many problems caused by the drought in the 1930s, through several shorter dry cycles experienced as recently as 2011. Drought can cause crops to fail, stress municipal water supplies, impact recreation, and make life generally miserable for anyone who makes their living from the land.

Drought certainly is not new to the region since the settlement era, with the most severe dry periods recorded in the 1930s, and more recently, the 1980s. Studies of isolated lakebeds in several places in North Dakota show that extreme fluctuations in the pattern of excessive precipitation and drought are normal. The studies found that in the case of the lakes, a variation between wet cycles and dry cycles have existed for thousands of years. Lakebed records indicate that since the glaciers receded, droughts and wet cycles lasting more than 100 years have occurred.

Although in an “average” year, there is often sufficient precipitation for the various uses that rely upon it, historical and paleoclimatological records indicate that there will be periods of time when there is not nearly enough moisture.

Image is of a lake elevation marker that no longer exists (where it stood, is now under more than 20 feet of water). The date on the picture is unsure, but can be dated prior to 1965 (likely 1940s). For reference, as of today, Devils Lake is at approximately an elevation of 1,452’ msl. Credit for this image goes to Chance Nolan, State Water Commission.

Q: Describe flooding in North Dakota
While droughts are common in the northern Great Plains, it is also true that this region experiences wet cycles. Climatologists believe that North Dakota is currently in a wet cycle that began in 1993, which has led to flooding throughout the state. It is useful to note that although we are believed to be in a long-term wet cycle on the eastern half of the state, mini-droughts can be experienced within that cycle. This has been the case in recent years, with drought afflicting western, and increasingly, eastern North Dakota.

Flooding in the Red River Valley in 1997 was the most severe in recorded history, when parts of the Red River Valley experienced a record-breaking 12 inches of snow, followed by a severe ice storm in the spring, and rapid spring melt. These factors, along with ice jams in several key areas, led to the catastrophic flooding that most visibly impacted the city of Grand Forks. It is worth noting that partial records indicate a flood more severe than the 1997 event occurred prior to European settlement.

With regard to the Devils Lake basin, in 1992, many in the state were concerned that the fishery was in imminent danger of dying off due to high salinity related to low lake levels caused by the late 1980s drought. In 1993, all of that changed, and with significant rainfall and snow runoff, the lake began to rise. The rise of Devils Lake has been relentless, with only the drought of 2011 and the operations of the Devils Lake Outlets causing significant reductions in lake levels.

Q: What climate trends has North Dakota experienced?
Several studies of lake sediment in North Dakota have demonstrated that the state is subject to long-term climatic variation, alternating between extended wet and dry cycles. Evidence has shown that the state does not really have a “normal” climate.

In recent years, climate change and global warming have gained greater attention. While the root causes of climate change, be they natural or human-induced, are still very much under debate, recent data does indicate that global temperatures have increased slightly. If warming trends continue, it is uncertain what effects North Dakota will experience. Climatological data inferred from lake core samples that provide a picture of climate in the region since the termination of the last ice age indicate that when global temperatures are warmer, North Dakota’s climate may not react in a predictable manner. With a wet cycle that has lasted for more than two decades, and models indicating a likelihood that current patterns could persist for decades more, regular flooding may become the new normal for much of the state.

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The image was generated using data collected by a statewide network of weather observers that work with the Atmospheric Resource Board (ARB) Division of the State Water Commission, for the growing season. Credit for this image goes to Chance Nolan, State Water Commission.