FIFTEENTH ANNUAL YEAR BOOK— PART XI 771 



of the month the weather was ideal, with high temperatures prevailing 

 most of the time. The first cool wave of the season spread over the State 

 between the 24th and 27th, causing the first Icilling frost in all sections, 

 except in the extreme northern corner of the State, where killing frost 

 occurred on the 15th. Light snow flurries, the first of the season, oc- 

 curred in the eastern counties on the 26th. 



The abundance of moisture in the soil, the lateness of the first oc- 

 currence of killing frost, and the pleasant weather during the latter half 

 of the month were ideal for farm work. All crops were matured under 

 favorable conditions, and much of the corn crop was harvested. Pastures, 

 meadows and fall sown grains were in excellent condition. 



Pressure. — The mean sea level pressure for the State was 34.04 inches. 

 The highest record was 30.52 inches at Sioux City, on the 24th, and the 

 lowest was 20.65 inches, at Sioux City, on the 4th. 



Temperature. — The monthly mean for the State, 108 stations reporting, 

 was 55.9°, or 5.1° above the normal, and only 8.6" below the average 

 for September. By sections the mean temperatures were as follows: 

 Northern, 55.0°, or 6.0° above the normal; Central, 55.9°, or 5.0° above the 

 normal; Southern, 56.8°, or 4.2° above the normal. Such a slight varia- 

 tion in the mean temperature of the several districts is unusual. The 

 highest monthly mean was 58.8° at Keokuk, and the lowest monthly mean 

 was 53.6°, at Rock Rapids. The highest temperature reported in the State 

 was 88° at Lenox, on the 1st, and the lowest was 14°, at Washta, on 

 the 27th. 



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

 88.0 per cent, and at 7 p. m. it was 71.4 per cent. The mean for the 

 month was 79.7 per cent, or about 7 per cent more than the normal. The 

 highest monthly mean was 88 per cent at Charles City, and the lowest, 

 76 per cent, at Sioux City. 



Precipitation. — The average for the State, 116 stations reporting, was 

 3.23 inches, or 0.77 inch more than the normal. By sections the averages 

 were as follows: Northern, 3.55 inches, or 1.21 inches more than the 

 normal; Central, 3.14 inches, or 0.65 inch more than the normal; Southern, 

 3.00 inches, or 0.46 inch more than the norrhal. The greatest amount re- 

 ported from any station was 6.64 inches, at Corning, and the least, 0.74 

 inch, at Le Mars. The greatest amount in any 24 consecutive hours, 4.63 

 inches, occurred at Corning, on the 8th. Showers occurred at some place 

 in the State every day between the 5tli and the 14th, with some heavy 

 local falls on the 6th, 7th and 8th. The first snow of the season fell in 

 Scott county on the 26th. Measurable precipitation occurred on an aver- 

 age of 9 days. 



"Wind.- — The prevailing direction of the wind was from the South. The 

 greatest velocity recorded was at the rate of 42 miles per hour from the 

 South, at Sioux City, on the 3d. 



Sunshine and Cloudiness. — The average percentage of the possible 

 amount of sunshine was 59 per cent, or about 10 per cent less than the 

 normal. The average number of clear days was 16; partly cloudy, 6; 

 cloudy, 9. , , 



