AREA-WEIGHTED SEASONAL TEMPERATURE AND PRECIPITATION NORMALS
Nebraska -- Selected Years
	Temperature					Precipitation
Period	Winter	Spring	Summer	Autumn	Annual Average	Winter	Spring	Summer	Autumn	Annual Total
1931-2000	25.6	47.7	72.3	50.2	49.0	0.58	2.38	3.09	1.45	22.47
1931-1960	25.7	47.4	73.1	50.9	49.3	0.62	2.27	2.96	1.29	21.37
1941-1970	25.5	47.1	72.1	50.4	48.8	0.59	2.26	3.30	1.40	22.63
1951-1980	24.8	47.3	72.2	50.1	48.6	0.56	2.35	3.13	1.38	22.27
1961-1990	24.8	48.0	72.0	49.8	48.6	0.55	2.46	3.10	1.52	22.90
1971-2000	25.7	48.2	71.8	49.5	48.8	0.55	2.60	3.11	1.60	23.60
Source: National Oceanic and Atmospheric Administration, National Climatic Data Center, Area-Weighted State, Regional, and National Monthly and Seasonal Temp. and Precip. 1971-2000 (and previous normals periods),  (HCS 4-1;2;3), 2003.
Last Updated:		3/3/08
by Nebraska Databook
email:	michael.lundeen@ded.ne.gov
The term climatic "normal" has faced a dilemma since its introduction a century and a half ago. As noted by Guttman (1989), "Climatologists generally understand that a normal is simply an average of a climatic element over thirty years.... a normal value is usually not the most frequent value nor the value above which half the cases fall."  The casual user, however, tends to (erroneously) perceive the normal as what they should expect.  Dr. Helmut E. Landsberg . . .  summarized the dilemma quite well over four decades ago (Landsberg, 1955):  "The layman is often misled by the word. In his every-day language the word normal means something ordinary or frequent. ...When (the meteorologist) talks about 'normal', it has nothing to do with a common event..... For the meteorologist the 'normal' is simply a point of departure or index which is convenient for keeping track of weather statistics..... We never expect to experience 'normal' weather."
It might be "normal" for the weather to swing radically between extremes from day to day and year to year, but the "climatic normal" is simply an arithmetic average of what has happened at such a "swinging" place. This is why it's important to use a measure of the variability of climate (such as the standard deviation and extremes) in conjunction with the climatic normal when studying the climate of a location (Guttman, 1989).
In accordance with national and international convention, the official climate normals computed for U.S. stations by NCDC consist of the arithmetic average of a meteorological element over 30 years.  The ‘official’ normals are provided solely by NCDC, which should be noted in light of other non-official means computations from a myriad of sources.  Source: National Climatic Data Center, Web site, December 2003.