Analyses were made of monthly and annual trends in temperatures at 25 rural stations located throughout contiguous USA (ie excluding Alaska and Hawaii). These stations were all at rural locations and were selected on the basis of their long records (generally over 100 years), their station quality (not near buildings, large trees, airports, etc) and the continuity of their records (generally less than 5% of missing data).
The analyses were of the raw temperature data (ie as originally recorded) without any “homogenisation” to account for missing data, changes in station location or for urbanisation effects.
The stations selected were assessed to be of good quality, based on the Surface Stations Project survey (2011) of 1007 US stations, and with largely-complete records of over a century. Furthermore, these records were to extend up to at least 2010 (but generally until 2014).
The mean monthly data were downloaded from the website of KNMI (The Royal Dutch Meteorological Institute).
Using Excel, simple plots were made of the annual mean temperature data. No estimates were made of missing data. A polynomial fit was made based on the full period of records.
CEDAR LAKE, WA 1909-2014
PRIEST RIVER, ID 1898-2014
UNION, OR 1911-2010
FENN RANGER STATION, ID 1908-2014
ABERDEEN, ID 1914-2014
MOCCASIN, MT 1909-2014
QUINCY, CA 1895-2014
FALLON, NV 1889-2014
FAIRMONT, CA 1911-2014
FORT VALLEY, AZ 1909-2014
LUNA, NM 1900-2014
JORNADA, NM 1914-2014
ELEPHANT BUTTE DAM, NM 1908-2014
TUCUMCARI, NM 1905-2014
CHEYENNE WELLS, CO 1897-2014
CRETE, NE 1893-2014
MORRIS, MN 1886-2014
CHATHAM, MI 1900-2014
SAINT JOSEPH, LA 1894-2014
PORT GIBSON, MS 1889-2014
KOSCIUSKO, MS 1889-2014
CROSSVILLE, TN 1912-2014
ROYAL OAK, MD 1893-2014
CHARLOTTEBURG RESERVOIR, NJ 1893-2014
SETAUKET STRONG, NY 1885-2012
Most stations exhibit a cyclical trend over the past century with maximums around 1920 or 1930 and minimums around 1980 or 1990.
About 70% of the stations have an overall neutral or negative trend over the past century.
This article was written by Brian Gunter Narooma, NSW. In his previous life Brian was an engineering hydrologist involved over many years in the analysis of rainfall and river flow of data for the planning of major water resources projects in Australia, Asia and Africa. In recent years he has been one of the Marine Rescue NSW (previously Royal Volunteer Coastal Patrol) volunteer weather observers who operate the Narooma station for the Bureau of Meteorology.