The quality controlled Iowa COOP data for June 2014 has been uploaded to the IEM. These observations are kindly provided by Harry Hillaker, our state climatologist, who passes along these notes on the month:

General Summary. Temperatures averaged 70.3° or 0.6°above normal while precipitation totaled 9.89 inches or 4.87 inches above normal.   This ranks as the 55th warmest and 3rd wettest June among 142 years of records.   The only calendar months with greater statewide precipitation averages were July 1993 (10.50”), June 2010 (10.39) and June 1947 (10.33).

Temperatures. Below normal temperatures prevailed on only nine days during the month, with the second week of June being especially cool.   Temperatures were above normal on all but two days over the last 16 days of the month but excessive heat never developed.   Temperatures reached into the nineties at only 21% of the reporting stations during the month with most of those in southwest Iowa.   The month’s highest temperatures were 93° readings at Sidney on the 18th and Little Sioux on the 20th.    Battle Creek reported the lowest temperature with 38° on the 13th.   A lower temperature had not been recorded so late in the season in Iowa since Cresco saw 35° on June 21, 1992.

Precipitation. Iowa came into June with much of the state in need of additional rainfall to replenish soil moisture reserves depleted by the very dry second one-half of 2013.  The wait for rain was quickly over with precipitation falling across all but extreme southeast Iowa on June 1st with locally heavy rain in portions of far northwest Iowa where Cherokee picked up 4.11 inches.   Rain also fell across all but far northeast Iowa on the 3rd with torrential rain falling across a sizable swath of southwest Iowa with Lamoni Airport recording 5.65 inches.   There was a welcome break in the rain until the 14th when excessive rain fell over much of northwest Iowa on the 14th-15th with Correctionville seeing 6.47 inches of rain.   Similar rains fell over the same areas of northwest Iowa on the 16th-17th with heavy rain also extending eastward through most of the northern one-half of the state.   Peterson reported the most rain with this event with 5.12 inches.   Record flooding commenced after this second major northwest Iowa rain event along the Rock and Big Sioux Rivers.   The rain focus then shifted to eastern Iowa with heavy rains on the 18th-19th including 5.12 inches at Postville.   Additional heavy rain totals included 4.27 inches near Council Bluffs on the 20th-21st, 5.45 inches near Adel on the 26th-27th and 6.11 inches at Muscatine on the 30th.   Monthly rain totals varied from 5.61 inches at Chariton to 17.00 inches at Cherokee.   An automated National Weather Service rain gage at Moville in Woodbury County recorded 18.70 inches of rain during June.   Record maximum rain totals for any calendar month were set at:

Station	June 2014 Total (inches)	Old Record	Period of Record
Cherokee	17.00	13.11 in Jun 2010	95 years
Emmetsburg	16.66	15.35 in Aug 2007	73 years
SiouxCity AP	16.65	11.78 in May 1903	136 years
Sioux Rapids	16.51	11.72 in Aug 1975	72 years
Rock Rapids	15.86	10.98 in Jun 1984	115 years
Le Mars	15.31	12.47 in Aug 1985	125 years
Holstein	14.20	13.42 in Jun 1967	81 years
Sanborn	13.91	12.28 in Jun 1891	102 years
Orange City	12.06	11.97 in May 2013	110 years

Cooling Degree Day Totals. Home air conditioning requirements, as estimated by cooling degree day totals, averaged 7% greater than last June and 8% greater than normal.   Air conditioning requirements for the year to date are running 14% greater than last year at this time and 12% greater than normal.

Severe Weather. Severe thunderstorms were reported on 15 dates during June with three major outbreaks on the 3rd, 16th and 30th.   The first large severe weather outbreak brought high winds and large hail to 12 southwest Iowa counties on the 3rd and was an extension of a much larger event across Nebraska.   Severe storms, mostly high wind events, were reported from 46 Iowa counties on the 16th with most coming over the northeast one-half of the state.   The final major event was on the 30th with 43 Iowa counties reporting large hail and/or high winds from northeastern Nebraska across the central one-third of the state and on into northern Illinois and southern Wisconsin.   Overall there were 31 confirmed tornadoes during the month, the largest monthly total in Iowa since 2008, but only one exceeded EF-1 intensity.

The following is the number of new daily records set at COOP sites based on data back to 1951.

                 2014__________________________2013______________
                 JUN  MAY  APR  MAR  FEB  JAN  DEC  NOV  OCT  SEP
Maximum High:     27   79  118   24   26   79   21   18   31  364
Minimum High:     37  235  174  406  306  219  141  170   60    9
Maximum Low:     122  102   40    7    7   22   14   25   46  213
Minimum Low:      58  171  209  439  379  194  177  241   70   32
Maximum Precip:  342   92  187   29   91   36   41  123  138   82

The following is some bulk statistics on how well IEM's daily COOP data estimator is performing on a monthly basis versus this QC'd dataset.

                 2014_______________________________2013_______
                 JUN   MAY   APR   MAR   FEB   JAN   DEC   NOV
High Temp Bias   0.1   0.2   0.4   1.3   1.4   0.8   0.7   1.1
High Temp RMSE   0.7   0.8   0.8   1.8   1.7   1.3   1.0   1.3
Low  Temp Bias   0.1   0.1   0.2   2.1   2.7   1.4   1.3   1.2
Low  Temp RMSE   0.8   0.9   1.0   2.4   2.9   1.6   1.6   1.5
Precip    Bias   0.13  0.20  0.14  0.36  0.31  0.49  0.24  0.09
Precip    RMSE   1.39  0.64  0.63  0.46  0.56  0.59  0.31  0.28