The year 2014 was Iowa's sixth-coolest year in 142 years of weather records. It was the coldest year for Iowa since 1917, says Harry Hillaker, state climatologist with the Iowa Department of Agriculture. Average temperature for the year was 45.4 degrees, which was about 2.7 degrees cooler than the 30-year average. Hillaker has analyzed the weather data for 2014 and prepared his annual summary for the year.
In 2014, February, July and November ranked in the top 10 coolest for those months on record in Iowa. Three months (June, October, December) had above-normal average temperatures in 2014, with June and October just barely warmer than normal.
What made 2014's average temperature cooler than normal was not so much having record-setting cold days, but rather it was "just persistently cold," Hillaker says. "Day after day, week after week, month after month it was just cooler than usual. The state's lowest temperature in 2014 was measured as minus 29 in Elkader on January 28 and February 11. He says the year's lowest temperature was a "typical winter extreme" and temperatures in Iowa have dropped to minus 30 in about half of the years on record.
Iowa's preliminary annual weather summary for 2014
The year's highest temperature of 97 degrees was "unusually low," says Hillaker. He also notes that the date it was measured, May 7, was "very early" in the year. He says 2014 ranked as the 15th wettest on record. The statewide average precipitation amount was 39.61 inches, about 4.34 inches above the 30-year normal. Historically, it was "fairly unusual to see that much rain in Iowa but the state has been getting more rain more frequently in the last several decades."
Last June was Iowa's third-wettest June in recorded history. April, August and September were also "quite a bit wetter than normal in most of the state. March and November were on the dry side.
The link to the weather summary Hillaker has posted on the Iowa Department of Agriculture & Land Stewardship website. It has maps and charts of annual precipitation across the state and has other weather data too. Here's the preliminary annual summary for 2014:
General summary: Iowa temperatures averaged 45.4° or 2.7° below normal while precipitation totaled 39.61 inches or 4.34 inches below normal. This ranks as the 6th coolest and 15th wettest year among 142 years of records. A colder year was last recorded in 1917 and a wetter one in 2010.
Temperatures. The year began with the coldest winter season in 35 years. February was the coldest month of the year, however, January felt even colder owing to frequent windy conditions (windiest calendar month at Des Moines since March 1986). Elkader recorded Iowa's lowest temperature of the year with -29° readings on January 28 and February 11 while the lowest wind chills were a pair of -51° readings on January 6 at Mason City and Oelwein. The persistent cold, along with relatively dry soils, allowed the ground to freeze to unusually great depths. Soils under sod froze to depths of two to three feet and under roadways to as much as five and one-half feet and resulted in hundreds of water main breaks across the state.
Soils finally thawed across southern Iowa in late March while some northern areas of the state remained frozen through the third week of April. A hard freeze was recorded over much of northwest Iowa on May 16 with the temperature falling to 24° at Spencer. This was the lowest temperature recorded so late in the spring in Iowa since 1963. The late freeze did necessitate replanting of some soybeans as far south as the Missouri border. The year's highest temperatures were 97° readings at Clarinda, Shenandoah and Sidney on May 7. Statewide there was an average of only three days with daily temperatures reaching 90° or above compared to the normal of 23 such days.
Iowa's earliest autumn freeze since 1986 impacted parts of northwest Iowa September 13. However, portions of southeast Iowa avoided a hard freeze until late in October. Overall, three months ranked among the 10 coldest in Iowa with February being the seventh coldest among 142 years of record for that month. July was the fifth coolest and November the fourth coldest. Only December averaged more than one degree warmer than normal.
Iowa entered the year 2014 with concerns about drought
Precipitation. Iowa entered the year 2014 with drought concerns, particularly over central and southeast sections, owing to the unusually dry weather prevailing during the second one-half of 2013. While much of Iowa recorded a very wet April, dry conditions persisted through May across the far northwest where Rock Rapids recorded its driest January through May period since 1963. However, northwest Iowa quickly collected its share of precipitation, and then some, during June. Rock Rapids received 11.04 inches of rain between June 14 and June 19. This 6-day total exceeded their highest calendar month rain total for any month among 116 years of records.
Record flooding followed along the Rock River. Heavy rain was widespread across northern and eastern Iowa for the remainder of June with widespread flooding. June precipitation totals were above normal at every Iowa reporting point with Moville in Woodbury County reporting the most rain with 18.70 inches. The statewide average precipitation for June was 9.92 inches and was the fourth highest calendar month total among 142 years of state records. Fortunately, rain subsided greatly across most of the state in July and brought a relatively quick end to flooding issues across Iowa.
Much of northeast Iowa turned relatively dry during mid to late summer and resulted in crop yields being trimmed from early expectations in those areas. But very wet weather redeveloped across much of the southwest one-third of Iowa in August and persisted in the same areas through mid-October. At Greenfield 17.95 inches of rain fell in August. Finally, as the year drew to a close, December was notable for a lack of snow over much of Iowa. Parts of eastern Iowa recorded no measurable snow during the month.
Total ranged from 25 inches at Hawarden to 55 inches at Greenfield
Annual precipitation totals varied from about 25 inches at Hawarden and Spirit Lake in the northwest to a little over 55 inches at Greenfield. Denison and Greenfield registered their wettest calendar years of record. Soil moisture levels at the end of the growing season were the greatest since 2010. The driest soils were in northwest Iowa, but even there moisture levels were far better than at the end of the three previous seasons. Very wet soils prevail over a broad swath of central and southwest Iowa, roughly bounded by Denison, Marshalltown and Lamoni Tornadoes.
The National Weather Service reported a total of 55 tornadoes across Iowa in 2014. This was the largest annual total since 2008 and follows below normal numbers in three of the previous four years. The bulk of the tornado activity came in early summer with 38 tornadoes reported in the three weeks between June 16 and July 6. However, the most noteworthy storm was an EF-1 intensity tornado that made a 46 mile path across
parts of four counties on April 26 and resulted in two fatalities in Keokuk County.
Crop production. Preliminary USDA data indicates that Iowa enjoyed a record corn yield of 183 bushels per acre and the second highest soybean yield of record at 52 bushels per acre. If realized the corn yield will be two bushels per acre greater than the previous high yield set in 2004 and 2009 while the statewide average soybean yield is
estimated to be one-half bushel per acre less than the record yield of 2005. Cold soils and frequent rains in mid-and late April got planting off to a slow start. However, much drier weather in May allowed rapid planting progress.
Heavy rains and flooding washed out some crops in June and necessitated some replanting, particularly in northern areas. However, growing conditions were nearly ideal during July with no damaging heat during the critical reproductive phase of crop development. The 2014 harvest got off to a very slow start owing to frequent rain in September and early October. Additionally, crop maturity and dry-down was slowed by the cool growing season, thus giving even less incentive to get into the fields early. Much drier weather from mid-October to early November allowed the harvest to be completed in a timely manner.
Editor's note: Harry J. Hillaker is the State Climatologist, Iowa Dept. of Agriculture & Land Stewardship, Wallace State Office Bldg., Des Moines, IA 50319. Telephone (515) 281-8981; E-mail [email protected].