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IOWA DEPARTMENT OF AGRICULTUEE. 



CLIMATE AND CROP REVIEW, 1907. 



The mean temperature and average precipitation for the state were 

 about the normal for the year, though the monthly averages were more 

 than usually variable. The mean temperature of the three winter months 

 was 24.2°, which is 3.6° above the normal. The mean of the spring was 

 45.2°, which is 0.9° above the normal. The mean of the summer was 

 70.1°, which is 1.7° below the normal. The mean of autumn was 49.9°, 

 which is 0.5° below the normal. February, March, November and De- 

 cember were much warmer than usual and all the other months were 

 deficient in temperature. The average of February was 5.8°, and March 

 7.6° above the normal. The greatest deficiency in temperature occurred 

 In April, May and June, the average of these three critical crop months 

 being about 6° below the normal. 



The average precipitation for the year, 31.62 inches, was 0.41 of an 

 inch below the normal. The records of four months showed an excess, 

 and the other months a deficiency in precipitation. The heaviest rainfall 

 occurred in June and July, and the most harmful deficiency of moisture 

 was in April and May, during the prevalence of abnormally cold weather. 

 The following table shows the monthly average temperatures and precipi- 

 tation, and departures from the normal for the year 1907: 



The above records show the abnormal features of the year, as affecting 

 the growth of staple crops and the harvest of hay and cereal products. 



The coldest weather of the winter occurred in the latter half of January 

 and the first week in February. This was followed by two weeks of 

 very mild weather, with favorable conditions for outside work and care 

 of stock. 



March was phenomenally mild with less than the usual amount of 

 precipitation. The first half was typical March weather, with alternate 

 freezing and thawing, but the latter half was excessively warm and bright, 

 the maximum temperatures during the last decade ranging above 70° 

 in portions of the southern section. The fields dried rapidly during 

 that warm period, and farming operations were begun ten days to two 

 weeks earlier than usual. The rainfall was less than normal, and the 

 greater part occurred in the first half of the month. With two exceptions 

 it was the warmest March since 1890. There was a great quickening of all 

 vegetation, and in the larger part of the state seeding was begun between 

 the 20th and 28th of the month, and a large acreage was plowed for corn. 



