Having digested overseas climate in recent years, I noted the record-warm January 1880 over the eastern US as exceptionally dry and cold over Western Europe – although similarly dry months there are not necessarily hot as far west as the US.
It is well-known that the contiguous US (CONUS) is by areal average much hotter than England and Wales in the northern summer, and colder in the winter. What I will try to do here is see how much variation there is between these normals, since the annual temperature means overlap somewhat. Since the CONUS averages a little hotter than England and Wales over the whole year, I will take positive as meaning the CONUS is hotter, negative that the CONUS is cooler than England and Wales.
Data exist for the years from 1895 to 2014, and I will do figures for fiscal year (July to June) as well as temperature. Fiscal year should provide a better picture than calendar year due to the greater influence of winter temperatures an annual variation, avoiding situations where unusually cold or warm winters are divided between two years.
|Month||# CONUS hotter||# CONUS cooler||Year of “highest” departure||Year of “lowest” departure|
It can be observed that some extremes, noted in red above, seem to be systematically influenced by man-made greenhouse gas emissions.
Although I could use an earlier date since rainfall records in the southern hemisphere indicate man-made global warming (countered in the northern hemisphere by short-lived aerosol pollution) was taking control of the climate as early as 1967, I will use the 1980 Lonie Report – which paved the way for major expansion of polluting freeways in by far the planet’s worst greenhouse polluter (Australia) – as a cut-off for “natural” variability. Previous records for those established since are:
- July “lowest”: 1976 (CONUS averaged 72.90˚F or 22.72˚C; CET was 18.7˚C or 65.66˚F)
- August “lowest”: 1975 (CONUS averaged 71.53˚F or 21.96˚C; CET was 18.7˚C or 65.66˚F)
- September “lowest”: 1949 (CONUS averaged 63.73˚F or 17.63˚C; CET was 16.3˚C or 61.34˚F)
- April “lowest”: 1944 (CONUS averaged 48.97˚F or 9.43˚C; CET was 10.2˚C or 50.36˚F)
- December “highest”: 1933 (CONUS averaged 36.43˚F or 2.46˚C; CET was 1.3˚C or 34.88˚F – though Scotland was actually milder than England or the CONUS)
- April “highest”: 1908 (CONUS averaged 52.75˚F or 11.53˚C; CET was 6.0˚C or 42.8˚F)
- February “highest”: 1954 (CONUS averaged a record 41.11˚F or 5.06˚C; CET was 2.6˚C or 36.68˚F)
|Temperature for the winter of 1916/1917. Note the uniform cold over most of the northern hemisphere apart from the subtropics, Central Asia, Greenland and Sakhalin.|