SEVENTEENTH ANNUAL YEAR BOOK— PART X 533 



divisions, three tiers of counties to the division, the means were as 

 follows: Northern, 78.6°, or 5.9° higher than the normal; Central, 

 79.9°, or 5.6° higher than the normal; Southern, 80.5°, or 6.4° higher 

 than the nonnal. The highest monthly mean was 83.5°, at Keokuk, and 

 the lowest was 75.2°, at Postville. The highest temperature reported 

 was 105°, at Ottumwa, on the 26th, and at Olin, on the 28th; the lowest 

 was 48°, at Estherville, on tlie 20th. The temperature range for the 

 state was 57°. 



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

 was 74 per cent, and at 7 p. m. it was 53 per cent. The mean for the 

 month was 64 per cent, or 4 per cent lower than the normal. The highest 

 monthly mean was 70 per cent, at Charleis City, and the lowest was 60 

 per cent, at Dubuque. 



Precipitation. — The average precipitation for the state, as shown by the 

 records of 115 stations, was 1.78 inches, or 2.18 inches less than the nor- 

 mal. By divisions the averages were as follows: Northern, 2.07 inches, or 

 1.81 inches less than the normal; Central, l.b9 inches, or 2.29 inches less 

 than the normal; Southern, 1.59 Inches, or 2.43 inches less than the 

 normal. The greatest amount, 6.87 inches, occurred at Cedar Rapids, 

 and the least, 0.10 of an inch, at Keokuk. The greatest amount in 24 

 consecutive hours, 4.46 inches, occurred at Cedar Rapids, on the 19th. 



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

 The highest velocity reported from a regular Weather Bureau station 

 was 37 miles an hour, fro^m the south, at Sioux City, on the 18th. 



Sunshine and Cloudines^s. — The average percent of the possible amount 

 of sunshine was 85, or 13 per cent more than the normal. The per cent 

 of the possible amount at the regular Weather Bureau stations was 

 as .follows: Charles City, 71; Davenport, 85; Des Moines, 91; Dubuque, 

 87; Keokuk, 80; Sioux City, 84. 



Miscellaneous Phenomena.— TiaXes, of: Hail: 2d, 12th, 17th, 22d, 23d, 

 24th; Thunderstorms, 2d, 3d, 4th, 8th, 9th, 11th to 25th, inc., 29th, 30th, 

 31st. 



Rivers. — The Mississippi at Dubuque was almost stationary at slightly 

 more than 9 feet during the first 10 days; then it rose to a maxlmuim 

 of 10.9 feet on the 20th, after which it fell steadily, reaching a minimum 

 of 8.0 feet at the end of the month. The average stage at that point was 

 9.8 feet, which is high for July. In the Davenport district the river 

 averaged almost 2 feet lower at the end of the month than at the begin- 

 ning, but good boating stages still prevailed. 



Storm of June 1, 1916. in Northeastern Iowa. — By J. H. Spencer, Meteor- 

 ologist, U. S. Weather Bureau. The storm in northeastern Iowa on June 

 1, 1916, was one of the most destructive on record in this part of the 

 state, owing to the resulting local floods. Exceptionally heavy rainfall 

 was recorded and it was the result of severe thunderstorms. These 

 storms occurred between 5:00 p. m. and midnight, and most of the rain 

 fell in less than three hours. At Decorah the amount of rainfall was 

 3,21 inches and the time of heaviest fall, between 5:30 p. m. and 7:00 

 p. m. The result of such heavy rainfall in such a short period of time 



