TWENTY-FIRST ANNUAL YEAR BOOK— PART VIII 655 



DECEMBER. 



Mild winter weather prevailed during the greater part of December and 

 the temperature was above normal continuously during the first 16 days. 

 From the 17th to the 28th the only cold weather occurred, with the tem- 

 perature below normal except on a few days. Cold waves, beginning on 

 the 22d and 26th, spread over the entire State but there were no unusually 

 low temperatures reported. The last three days were warm. 



Conditions were generally favorable for out door work and stock. Until 

 the cold weather set in very little frost was in the ground and plowing 

 was reported from many places during the greater portion of the second 

 week. During the cold weather winter grain was well protected by snow 

 and the condition at the end of the month was good. 



Rain or sleet fell in the south and east portion of the State on the 3d-4th. 

 On the 13th the first well defined snowstorm reached from southwest to 

 northeast across the State and extended to the Mississippi by the morn- 

 ing of the 14th. Amounts up to 7.0 inches occurred at stations in the 

 central counties. The snowstorm of the 20th-22d covered the entire State 

 except a small area in the east-central division. Considerably more than 

 10 inches fell in areas in the northern and west-central divisions. At 

 Sioux City the 24-hour fall, 13.6 inches, is the greatest of record in Decem- 

 ber. This snow drifted badly and resulted in considerable delay to street 

 car and automobile traffic. The snowstorm of the 25th-26th was confined 

 to the eastern half of the State, and the amounts were generally light 

 except over the southeastern district. After the ground became covered it 

 remained so during the rest of the month over practically the entire 

 State, but was becoming bare at the close of the month. 



Thunderstorms, though unusual in December, occurred on the 3d, 4th 

 and 13th at a large number of stations, particularly in the eastern portion 

 of the State. At Dubuque thunderstorms occurred on the 3d and 13th. 

 At this station thunderstorms have been recorded only three times in 

 December during the last 46 years and never before have two occurred in 

 one December. 



An extensive glaze storm occurred in connection with the storm of the 

 20th-22d. It was preceded by a general snow cover, so no damage to 

 winter grains and grass is believed to have resulted. 



Pressure. The mean pressure (reduced to sea level) for the State was 

 29.97 inches. The highest recorded was 30.52 inches, at Omaha, Neb., on 

 the 24th and the lowest was 29.00 inches, at Dubuque, (the lowest of 

 record for December) on the 13th. The monthly range was 1.52 inches. 



Temperature. The mean temperature for the State, as shown by the 

 record of 99 stations, was 26.4°, or 2.5° higher than the normal. By 

 divisions, three tiers of counties to the division, the mean temperatures 

 were as follows: Northern, 23.6°, or 2.4° higher than the normal; Cen- 

 tral, 26.7°, or 2.6° higher than the normal; Southern, 29.0°, or 2.5° 

 higher than the normal. The highest monthly mean was 32.8°, at Keo- 

 kuk, and the lowest was 20.8° at Inwood. The highest temperature 



