The top 10 coldest years in Chicago in this period were the following:
1- 1951: 8,2C
2- 1972: 8,4C
3- 1985: 8,6C
4- 1996: 8,7C
5- 1958: 8,8C
6- 1963: 8,8C
7- 1967: 8,9C
8- 1978: 9,0C
9- 1982: 9,0C
10- 1976: 9,1C
As we can see, none of this years were held in the new millennium. Actually, five of the top 10 warmest years in Chicago occured after 2000, and 2012 was the warmest in the whole period. Nevertheless, it is very likely that 2014 might become a new member of the top 10 list of cold years, with a very high probability to find a place in the podium! If december ends around its average, 2014 must register 8,5C, taking up the 1985 third position. Let us see if it happens. It would be a remarkable event in a time of warming trend.
Talking about seasons we can have different findings, so the four seasons will be analyzed separately.
Summer (JJA)
Along with spring, it is the season that is presenting the major warming trend decade by decade. It is heating up since the 60's after becoming cooler when compared with the 50's. The last four summers played a very important role for it, specially the years 2011 and 2012. Both registered the warmest julies ever. June 2012 also took off and reached the second place amongst the entire series. After that it is impossible not to think that the JJ period of 2012 was by far the hottest ever recorded.
Fall (SON)
Chicago's fall has experienced a steady no-warming period since the city entered the 60's. It is not possible to recognize any up trend, neither down trend in its temperature in the last 54 years. Thus, the top 5 coolest and 5 warmest SON do not concentrate years of any decade. Even in the 50's, the coldest decade for falls, it wasn't as much colder from nowadays.
Winter (DJF)
The winter in Chicago now is at the same stage seen in the 50's where the average temperature was -2,9C. The course followed by winters through decades varied widely, though. It happened because in the 60's and 70's the winters were extremely colds, specially 1963, which the DJF average had the incredible mark of -9,7C. In the 70's there were two bitterly cold winter as well: 1977 (-6,4C) and 1978 (-6,6C). To realize how cold it was, the normal temperature for DJF nowadays is -2,7C...
The 60's and 70's influenced the numbers seen in the 1961/1990 and 1991/2014 normals. The first one became much colder than the second one. Hence, thinking about this kind of comparison (normal vs normal), winter in Chicago is the season which faced the major warming trend among the three others. The Excel Sheets in the end of this post will illustrate better.
A very interesting thing regarding this warming trend is the fact that 2014 experienced the third coldest January/February (JF) in the whole series. Hence, if december strive, it might bring a strange spot in the line of trend.
Spring (MAM)
As it was previously said, the spring is getting warmer in Chicago. It used to be colder in the 50's and 60's, and now the city is facing its warmest springs since 1951. Considering the top 10 hottest MAM of the series, four occured in the new millennium: 2007, 2000, 2010 and 2012. The last one once more in the first place. In the other hand, four of the 10 coldest springs were from 50's and 60's.
Conclusion: will 2014 be only a "cold island" in he middle of the "desert" or will it mean the begining of a new era of cooling for Chicago? Only god knows...
Bellow the Chicago O'Hare data:
Source: NASA GISSTEMP (
http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=425725300000&dt=1&ds=14
) & TU TIEMPO (
http://www.tutiempo.net/clima/CHICAGO_OHARE_INTL/725300.htm )
From
january/1951 to october/1960; from november/1963 to august/1965; and in
december/1989, the data were collected from TU TIEMPO web site due to
missing data in NASA GISSTEMP.
I hope you all enjoy the numbers and feel free to criticize!
Cheers,
Bruno
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