564 TWENTY-THIRD ANNUAL YEAR BOOK— PART VIII 



the year was 29.98 inches, or 1.99 inches less than normal, and 2.05 inches 

 less than the average for 1921. The greatest amount at any station was 

 44.20 inches, at Mt. Ayr, Ringgold County, and the least amount was 

 19.08 inches, in Dickinson County, near Milford. The greatest monthly 

 precipitation was 11.72 inches, at Mt. Ayr, Ringgold County, in July. The 

 least amount was a trace at Cumberland, Glenwood, Harlan, and Thur- 

 man in southwest Iowa, in December. The greatest amount in any 24 con- 

 secutive hours was 5.83 inches, at Atlantic on August 30. Measurable 

 precipitation occurred on ah average of 84 days, 2 days less than in 1921 

 and one day less than normal. 



Snowfall. The average amount of snowfall was 13.5 inches. The 

 greatest amount reported from any station was 38.9 inches at Sioux 

 Center, Sioux County, and the least amount was 2.0 inches at Bonaparte, 

 Van Buren County. The greatest monthly snowfall was 23.0 inches at 

 Rockwell City, Calhoun County, in January. 



Wind. The prevailing direction of the wind was from the south. The 

 highest velocity reported was 67 miles an hour from the south at Sioux 

 City, Woodbury County, on June 8. 



Sunshine and Cloudiness. The average number of clear days was 1S7; 

 partly cloudy, 89; cloudy, 89; as against 171 clear, 99 partly cloudy, and 

 95 cloudy days in 1921. The average percentage of the possible amount 

 of sunshine was 62 or about 1 per cent more than the normal. 



MONTHLY SUMMARIES 

 JANUARY 



January as a whole was a pleasant month, though subject to an unusual 

 number of fluctuations above and below the normal, and there were some 

 great extremes in temperatue, particularly on the 6th, when the minimum 

 temperature ranged from 29 degrees below zero at Charles City to 11 

 above at Keokuk. The mean temperature averaged somewhat above nor- 

 mal, with an excess at every station except Mason City, and the mean was 

 least over northern districts, where the ground was snow covered the en- 

 tire month, except the first three days, and gradually increased to the 

 south where the ground was covere-d on an average of less than 10 days. 

 Zero weather was reported throughout the State except a small area along 

 the Mississippi River in the extreme southeast corner. 



Precipitation averaged slightly below normal, being slightly above 

 normal over the northern division and somewhat below in the central and 

 southern divisions. More than 75 per cent of the monthly total occurred 

 during the storm of the 4th-5th, which was in the form of snow over the 

 northern half of the State and rain over the southern half. The snow- 

 fall during this storm ranged as high as 14 inches and in sections drifted 

 enough to interfere with wagon and automobile traffic but not enough to 

 seriously delay rail traffic. Over the southern division and portions of 

 the central division the precipitation in this storm was in the form of 

 rain, which froze to all exposed surfaces. This general icy condition con- 

 tinued for several days, and in protected places, till the close of the 



