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1930s Dustbowl Still Dominates Heat Records

By Joe D'Aleo
Monday, June 23, 2008

After a spring that ended the 36th coolest in 114 years and for many areas of the central areas one of the wettest, many are wishing for more warmth and dryness.


Two weeks ago, we did a story on how soil moisture conditions in the spring usually persist through the following summer and affect temperatures. This year that should mean heat will be limited in the wet areas of the central and likely more persistent over drought areas well to the south and west. That contrast should mean more of the same in terms of storms feeding off the heat and available moisture, bringing more tornadoes and flooding rains.


Last week we did a comparison to 1993, a record flood year. The rains so far have exceeded the rains in the flood year of 1993 in Iowa with over 20 inches in the northeast in the 60 days ending early June. This has led to massive, all time record floods, failures of at least 20 levees and losses of between 5 and 9% of the corn and bean crop. . 



This week, we are going to focus on the 1930s, the Dust Bowl years where the opposite conditions prevailed and persisted for most of a decade. We will show how the dry ground, helped make the 1930s the hottest decade in history.


Though Iowa was not ground zero for the 1930s drought, the persistent dryness in the south central built the central heat ridge further and further north eventually setting all time records in many states, including Iowa.



Technically, the driest region of the Plains – southeastern Colorado, southwest Kansas and the panhandles of Oklahoma and Texas – became known as the Dust Bowl, and many dust storms started there. But the entire region, and eventually the entire country, was affected.




The Dust Bowl got its name after Black Sunday, April 14, 1935. More and more dust storms had been blowing up in the years leading up to that day. In 1932, 14 dust storms were recorded on the Plains. In 1933, there were 38 storms. By 1934, it was estimated that 100 million acres of farmland had lost all or most of the topsoil to the winds. By April 1935, there had been weeks of dust storms, but the cloud that appeared on the horizon that Sunday, the 14th, was the worst. Winds were clocked at 60 mph. Day became night.



The day after Black Sunday, an Associated Press reporter used the term "Dust Bowl" for the first time. In the central and northern plains, dust was everywhere.

The dust bowl was caused not just by the dry weather but also by unwise farming practices. Earlier settlers plowed under the natural tall grasses that covered the plains and planted crops they had planted in the wetter East. When the drought came, the crops failed, the ground was uncovered and the incessant winds produced the dust storms.



After the dust bowl, farmers ended over-cropping, over-grazing and improper farm methods. Since then wheat which is tolerant of drier conditions was grown in the semiarid west and other crops further east

As we indicated last week, dry ground enhances heat. Heat can expand north and east (sometimes even west). This can be clearly seen in the plot of record highs for Des Moines, Iowa for June and July. Note 33 of the records were in the 1930s and interestingly none since 1988.





Winter records are more evenly spread over the decades with a peak in the 1980s. The 1930s still shows some strength. They may reflect the urban growth of Des Moines.



The state records also show the dominance of the 1930s. See this blog by Bruce Hall of the Hall of Records. Scroll down to the bottom of the page and see some monthly state records for a hand full of states. Note the dominance of the 1930s in Nebraska, Oregon, Pennsylvania.



In fact for the 50 states, 24 of the all-time hottest temperature records occurred in the 1930s.






Dust storm approaching Stratford, Texas Dust bowl surveying in Texas
Image ID: theb1366, Historic C&GS Collection
Location: Stratford, Texas
Photo Date: April 18, 1935
Credit: NOAA George E. Marsh Album



Dust storm approaching Stratford, Texas Dust bowl surveying in Texas
Image ID: theb1365, Historic C&GS Collection
Location: Stratford, Texas
Photo Date: April 18, 1935
Credit: NOAA George E. Marsh Album