TWELFTH ANNUAL YEAR BOOK— PART I 15 



is 2.26 inches below the normal. The greatest amount, 9.47 inches, oc- 

 curred at Ridgeway, Winnishiek County, and the least, 0.44 inch, at Chari- 

 ton, Lucas County. The greatest amount in twenty-four hours, 3.75 inches, 

 occurred at Dubuque, Dubuque County, on the 10-llth. Measurable preci- 

 pitation occurred on an average of 9 days. 



Sunshine and Cloudiness. — The average number of clear days was 16; 

 partly cloudy, 10; cloudy, 5. The duration of sunshine was about the nor- 

 mal, the percentage of the possible amount being 76 at Charles City; 75 

 at Davenport; 75 at Des Moines; 63 at Dubuque; 76 at Keokuk; and 70 

 at Sioux City. 



Wind. — Southeast winds prevailed. The highest velocity reported was 

 42 miles per hour from the west, at Sioux City, Woodbury County, on the 

 6th. 



SEPTEMBER. 



From the view point of the agriculturist, September, 1911, was a very 

 favorable month. The temperature was above the normal, and no damag- 

 ing frosts occurred. The drought that had prevailed during most of the 

 crop season, in the southern and western counties, was broken, and all 

 parts of the state received copious to heavy rains and at the close of the 

 month there was abundance of water for all purposes. Water was flowing 

 in many small streams for the first time since May; grass was green and 

 growing rapidly; the ground was soft and moist and much plowing and 

 seeding had been done and fall grains were looking well; practically all of 

 the corn was ripe and beyond danger of injury by frost, and late potatoes 

 that on September Ist were thought to be a failure give promise of good 

 yields. The only real hot day was the 1st, when the temperature was 90°, 

 or above, except in the extreme northern part of the state. The rest of 

 the time the temperature was moderate, but it was about normal or slight- 

 ly above most of the time. The coldest day was on the 19th, when mini- 

 mum temperatures of 32° were recorded at 3 stations. This low mark, is, 

 with one exception, the highest September minimum recorded in the state 

 during the past 22 years. In September, 1905, the lowest temperature re- 

 corded in the state was 36°. 



The average rainfall is 5.12 inches, which is the greatest amount re- 

 corded in Iowa during September since state-wide observations began in 

 1890. Showers were fairly well distributed throughout the month, but 

 the amounts of rainfall were much greater in the southeastern counties 

 than in other parts of the state. In the southwestern and west central 

 districts, where the drought had been the most severe, the rainfall was 

 generally light until near the close of the month, but heavy showers oc- 

 curred in those sections on the 28th and SOth. In the southeastern coun- 

 ties the rainfall was excessively heavy, and in many localities caused con- 

 siderable damage. Bottom lands were overflowed and corn in shock ma- 

 terially injured. Thunderstorm's were frequent and more than the usual 

 amount of damage was done by lightning. In a few cases the thunder- 

 storms were accompanied by severe wind squalls, but the only storm of a 

 tornado character occurred in Madison County on the afternoon of the 

 6th. 



