484 IOWA DEPARTMENT OP AGRICULTURE 



counties, precipitation was greatly deficient so that little or no fall plow- 

 ing could be done and less than the usual acreage of winter wheat and rye 

 could be sown. Just east of the divide from Greene southeastward to 

 Lucas counties and in the eastern counties from Clinton and Cedar to 

 Henry and Des Moines, there was a marked excess in precipitation. In 

 other sections the precipitation was about normal in frequency and 

 amount. There was a marked increase in the acreage of winter grains 

 sown In the northern division. In the southern division the acreage, 

 where conditions were favorable, was about the same as that sown in 

 1916. 



In the areas of deficient precipitation, pastures failed, stock was ex- 

 tensively fed, and the potato crop will be moderate to light. 



Pressure. — The mean pressure (reduced to sea level) for the State was 

 30.09 inches. The highest recorded was 30.63 inches, at Dubuque, on the 

 10th. and the lowest was 29.75 inches, at Sioux City, on the 27th. The 

 monthly range was 0.88 inch. 



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

 records of 102 stations, was 62.6°, or 0.8° below the normal. By divisions, 

 three tiers of counties to the division, the means were as follows: North- 

 ern, 60.6°, or 1.2° below the normal; Central, 62.6°, or 0.9° below the 

 normal; Southern, 64.6°, or 0.4° below the normal. The highest monthly 

 mean was 66.2°, at Northboro, and the lowest was 58.3°, at Decorah, 

 Estherville, and Postville. The highest temperature reported was 97°, 

 at Clarinda, on the 3d; the lowest was 28°, at Sibley, on the 27th. 

 The range for the State was 69°. 



Precipitation. — The average precipitation for the State, as shown by the 

 records of 106 stations, was 2.90 inches, or 0.46 inch less than the nor- 

 mal. By divisions, the averages were as follows: Northern, 2.85 inches, 

 or 0.20 inch less than the normal; Central, 3.03 inches, or 0.43 inch less 

 than the normal; Southern, 2.81 inches, or 0.75 inch less than the normal. 



The greatest amount, 8.68 inches, occurred at St. Charles, and at least, 

 0.39 inch, at Audubon. The greatest amount in 24 consecutive hours, 

 5.74 inches, occurred at St. Charles on the 4th. 



Humidity. — The average relative humidity for the State at 7 a. m. 

 was 85 per cent, and at 7 p. m. 65 per cent. The mean for the month was 

 75 per cent, or 1 per cent higher than the normal. The highest monthly 

 mean was 80 per cent, at Charles City, and the lowest was 71 per cent 

 at Omaha, Nebr. 



Wind. — The prevailing direction of the wind was from the southeast. 

 The highest velocity reported from a regular Weather Bureau Station 

 was 40 miles an hour from the west, at Sioux City on the 18th. 



Sunshine and Cloudiness. — The average per cent of the possible amount 

 of sunshine was 59 per cent, or 4 per cent less than the normal. The 

 per cent of the possible amount at the regular Weather Bureau stations 

 was as follows: Charles City, 48; Davenport, 59; Des Moines, 54; Du- 

 buque, 63; Keokuk, 69; Sioux City, 54; Omaha, Nebr., 67. 



