This post refers to my analysis of recorded monthly mean temperature trends at Aberdeen in Idaho, USA. The station was established in 1914. The analysis used raw data (as recorded, without any adjustments) as published by KNMI (the Dutch Meteorological Institute). Polynomial curves of best fit were added to the plots.
Aberdeen is located at an agricultural research station near the town of Aberdeen in southeastern Idaho, USA. The station is at an elevation of 1340 m.
Over the 1914-2016 period (a period of 103 years) the years are 91% complete.
Aberdeen has a steppe climate, with cold winters and mild summers. Mean monthly temperatures vary from -6.1 degC (in January) to +20.5 degC (in July). Extreme monthly mean temperatures recorded are -16.6 degC (in January 1949) to +24.1 degC (in July 2007).
Mean, Maximum and Minimum Monthly Temperatures
Plots are shown below for annual mean temperature and the monthly mean temperature for each of the 12 months. A polynomial trendline was fitted to each graph. A comparison of the monthy trendlines are also presented. It should be noted that the trendlines (in red) can sometimes be misleading at either end of the series as the line is very dependent on the temperature values in individual years (this sensitivity does not occur away from the start and end of the series).
Annual Mean Temperatures
Monthly Mean Temperature Trendlines
- The plots show cyclical monthly trendlines in most months, with Highs in about 1940 and 2010 and a Low in about 1980.
- The monthly mean temperatures trends around 2000-2010 vary from about 1.5 degC lower to about 1 degC higher than in about 1940.
- The long-term average trend is about -0.5 degC/century.
- In most months there is a peak or plateau in the temperature trends around 2000-2010.
- There have been no alarming trends in temperatures in recent decades.
Aberdeen is one of 257 stations, worldwide, for which I have analysed long-term temperature trends. The analyses at 50 representative stations are summarised in the blog post: world-50-temperatures
Please let me know what you think of my analyses. firstname.lastname@example.org
This article was written by Brian Gunter of Narooma, NSW, Australia. In his previous life Brian was an engineering hydrologist involved over many years in the analysis of rainfall and river flow data for the planning of 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 Australian Bureau of Meteorology.