532 IOWA DEPARTMENT OP AGRICULTURE 



JULY. 



July, 1916, in Iowa will be long notable in the climatological annals 

 of the state as a period of extreme heat and dryness. With the single 

 exception of the memorable July of 1901 it was the warmest month 

 of record in Iowa, and of all Julys, that of 1894 alone was drier. The 

 month will be noteworthy more for its general warmth as a whole thaa 

 for any excessively high temperatures that occurred. Although ther- 

 mometer readings exceeding 100" were common on a number of days, 

 yet the absolute highest temperature reported was but 105°; this is 

 several degrees lower than the figures attained in a number of otner 

 years. Since the mean temperature from day to day was almost con- 

 tinuously above the normal it can not be said that the month had any 

 cool periods. As a rule monthly minimum temperatures at the individual 

 stations were as high or higher than any similar record in the past. 

 The hottest part of the month comprised the 7-day period ending on 

 the 30th, which was, with two exceptions, the warmest week of record 

 in Iowa. 



The average precipitation for the whole state was considerably leisis 

 than one-half the normal, and only six stations reported an excess. While 

 the showers came at rather timely intervals, especially during the hrst 

 two decades of the month, the geographical distribution was decidedly 

 irregular, as may be seen by reference to the precipitation chart at 

 the end of this report. An extreme illustration of this irregularity 

 is afforded by the records of two rain gauges in Des Moines. The gauge 

 at the regular Weather Bureau station caught 1.50 inches, w'hile another 

 not two miles distant showed a 'fall of 3.03 incihes. In some localities 

 moisture was needed early in the month, but actual droughty conditions 

 did not set in until the last decade. At that time all vegetation was in 

 urgent want of rain, and potatoes, garden truck and pastures were suf- 

 fering severely, wihile corn was imperiled. Fortunately, showers occurred 

 on the 31st in a number of localities and were highly beneficial, but in 

 other districts either no rain fell or the amounts were inadequate. 



Naturally, the extreme heat was trying to both man and beast. 

 Many persons were prostrated — some fatally, and a large number of ani- 

 mals died. In some cases manufacturing establishments either sus- 

 pended or curtailed operations at the time of the most intense heat. 

 That the drawbacks of the month had in isome degree their compensations 

 is indicated from the fact that the weather was exceptionally favorable 

 for harvesting and threshing owing to the large number of clear, sun- 

 shiny days. The amount of sunshine was among the greatest ever recorded 

 in Iowa in any month. 



PreSfSure. — The mean pressure (reduced to sea level) for the state 

 was 29.97 inches. The highest recorded was 30.27 inches, at Sioux City, 

 on the 31st, and the lowest was 29.72, at Davenport, on the 2d, and at 

 Sioux City, on the 3d. The monthly range was 0.55 of an inch. 



Temperature. — The mean temperature for the state, as shown by the 

 records of 105 stations, was 79.7°, or 5.6° higher than the normal. By 



