THIRTEENTH ANNUAL YEAR BOOK— PART I 17 



Southwesterly winds prevailed. The highest velocity reported was 39 

 miles an hour from the south, at Sioux City, Woodbury County, on the 

 11th. 



AUGUST NORMALS FOR IOWA, 1890—1912. 



Normal temperature for August, 71.7°. 



Warmest August, 1900, with mean temperature of 77.4". 



Coldest August, 1890, with mean temperature of 68.4°. 



Normal August precipitation, 3.61 inches. 



Wettest August, 1903, with total precipitation of 6.64 inches. 



Driest August, 1901, with total precipitation of 1.29 inches. 



Average number of days with 0.01 inch or more of precipitation, 7. 



Prevailing direction of wind, south. 



Average number of clear days, 16; partly cloudy, 10; cloudy, 5. 



SEPTEMBER. 



The period of high temperatures that began on August 30th continued 

 until September 9th, the temperature gradually increasing, and culminat- 

 ing with readings above the century mark at several stations in the south- 

 ern section on the 8th and 9th. The highest temperature reported was 

 104° at Ottumwa on the 8th. Much cooler weather prevailed after the 

 9th, and the temperature was below the normal nearly every day after the 

 12th; the lowest occurring generally on the 26th or 29th, when heavy to 

 killing frosts with temperatures near or below the freezing point were re- 

 ported from all sections of the state. Showers were frequent and the 

 amounts of rainfall were fairly well distributed, except over Jefferson, 

 Wapello, Davis and Appanoose Counties, where the total for the month 

 was considerably less than one inch. The greatest amounts are reported 

 from the west-central counties. Rain fell somewhere in the State on every 

 day of the month except the 30th; and as a result threshing was delayed 

 and considerable grain in shock and stacks was damaged. The rains, how- 

 ever, put the ground in excellent condition for fall plowing and seeding, 

 and were very beneficial to pastures and meadows. Corn made unusually 

 rapid progress toward maturity during the first 12 days of the month, but 

 the cool weather following checked the rapid development, and about 20 

 per cent of the crop was more or less damaged by the killing frosts and 

 freezing temperatures during the last week. The total yield will, however, 

 be greater than was ever before produced in the State. 



Temperatuee. — The monthly mean temperature for the State, as shown 

 by the records of 109 stations, was 62.1°, or 1.6° less than the normal. By 

 sections the mean temperatures were as follows: Northern, 60.3°, or 1.8° 

 less than the normal; Central, 62.2°, or 1.4° less than the normal; Southern 

 63.7°, or 1.8° less than the normal. The highest monthly mean was 67.4°, 

 at Keokuk, Lee County, and the lowest monthly mean was 57.6°, at Rock 

 Rapids, Lyon County, and at Sibley, Osceola County. The highest temper- 

 ature reported was 104°, at Ottumwa, Wapello County, on the 8th; the 

 lowest temperature reported was 24°, at Bedford, Taylor County, on the 

 26th and 30th. The average monthly maximum was 95°, and the average 

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