586 TWENTY-THIRD ANNUAL YEAR BOOK— PART VIII 



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

 79 per cent, and at 7 p. m. it was 57 per cent. The mean for the State was 

 68 per cent, which is the normal. The highest monthly mean was 72 per 

 cent, at Charles City, and the lowest was 62 per cent at Keokuk. 



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

 the records of 100 stations, was 6.31 inches, or 2.35 inches more than the 

 normal. By divisions the means were as follows: Northern, 5.23 inches, 

 or 1.35 inches more than the normal; Central, 6.59 inches, or 2.61 inches 

 more than the normal; Southern, 7.11 inches, or 3.C9 inches more than 

 the normal. The greatest amount, 11.72 inches, occurred at Mt. Ayr, and 

 the least, 3.13 inches, at Northwood. The greatest amount in 24 con- 

 secutive hours was 4.32 at Fayette, on the 6th and 7th. 



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

 highest velocity reported from a regular Weather Bureau station was 

 48 miles per hour, from the northeast, at Sioux City, on the 8th. 



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

 of sunshine was 64, or 10 per cent less than the normal. The per cent of 

 the possible amount at the regular Weather Bureau stations was as fol- 

 lows: Charles City, 65; Davenport, 65; Des Moines, 56; Dubuque, 60; 

 Keokuk, 75; Sioux City, 53; Omaha, Nebr., 74. 



Miscellaneous Phenomena. Fog: 11th, 30th. Hail: 5th, 6th, 8th, 9th, 

 15th, 16th, 25th, 26th, 28th, 30th. Halos (Lunar and Solar): 6th, 11th, 

 20th, 21st, 28th. Rainbow: 15th, 31st. Thunderstorms: all dates during 

 the month except 3d, 4th, 13th, 18th. Tornado: 16th, 29th. 



Rivers. Moderate stages prevailed on the principal rivers with very 

 little change except following the heavy rainstorms. Stages were gen- 

 erally low in the interior rivers, though rather high in the lower reaches 

 of the Des Moines and Skunk Rivers following the heaviest rains. Most 

 of the rains were absorbed by the soil and the run-off was gradual. 



