Where’s the Warming in Portland, Maine?

I’m 73 years old, and I don’t think that it’s any warmer today than when I was a kid. In fact, I remember some summers much hotter than nowadays, but that’s mere anecdote and subject to all the vagaries of memory. Being a skeptic concerning global warming as well as man-made global warming, I decided to do some simple research.
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Being from New England and still having family there, I decided to check the temperatures on a given day in July for as far back as I could find an official record. Portland, Maine has an official weather station. I chose July 26 for a date. I was able to obtain the official high and low temperatures for that date for the years 1961 to 2014; 2008 and 2009 were unavailable, so I’ve recorded the monthly average high and low temperatures for those two years. This makes no difference at all in what I found.

Here are the data for year, high, and low temperatures on July 26 in Portland, Maine.

July 26
1961 86 64
1962 71 57
1963 99 65
1964 75 58
1965 84 55
1966 82 62
1967 82 60
1968 83 57
1969 64 59
1970 86 64
1971 76 61
1972 80 58
1973 80 64
1974 70 53
1975 77 52
1976 75 45
1977 71 48
1978 75 55
1979 81 67
1980 85 61
1981 75 61
1982 88 66
1983 82 57
1984 78 51
1985 74 63
1986 88 65
1987 86 64
1988 74 62
1989 95 69
1990 83 64
1991 72 61
1992 78 52
1993 73 57
1994 82 63
1995 83 68
1996 80 55
1997 89 53
1998 78 53
1999 75 63
2000 73 55
2001 72 53
2002 69 49
2003 86 60
2004 74 58
2005 87 64
2006 82 67
2007 85 65
2008 80 61 (Month average)
2009 74 58 (Month average)
2010 82 57
2011 74 62
2012 73 61
2013 72 62
2014 80 57

I challenge anyone to find any evidence whatsoever in these data that there has been a warming trend over these years.

To supplement these data, we can use some averages supplied by the U.S. weather service. They say that the years 1971-2000 (30 years) had a July average monthly high of 78.8, and they say that the 70-years 1941-2010 averaged 79.0 The average lows were 58.6 and 58.2, respectively. Mathematically, it has to be the case that the combined years 1941-1970 and 2001-2010 averaged almost exactly the same as the years 1971-2000. This again provides no evidence of global warming in Portland, Maine during the period 1941-2010.

There are other ways to look at these data. We can look for runs of hot and cold years by ranking warmest to coldest (for July). The weather service does this for 1941-2010.

The 10 hottest maxima from hotter to cooler are

1952 (84.7 degrees); 1955; 1949; 1994; 2010; 1948; 1999; 2006; 1959; 1968 (81.0 degrees)

These average 1974.

The 10 coolest maxima are as follows from warmer to cooler:

1956 (76.2 degrees); 1961; 1969; 1962; 1967; 1986; 1992; 1996; 2004; 2009 (74 degrees)

These average 1980.

Hence, if we look at extremes of the extremes, the hotter July months occurred earlier in time, since they average 1974, and the cooler ones occurred later in time, since they average 1980.

There is no evidence here that’s consistent with global warming.

This is one experiment only. It confirms my personal experience.

Consider the difficulties of repeating this experiment for other locations and periods, and then consider the difficulties of accounting for the variations that will surely occur. Some will show no change. Some will show warming. Some will show cooling. There will be cross-sectional sampling variation and its significance must be ascertained. The distributions may not be normal. They’ll probably show marked kurtosis. Then this has to be done globally. Then after that one needs models of climate changes and variations not caused by mankind. Unless this kind of careful work has been done convincingly, the science behind the global warming hypothesis will be controversial.

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10:00 am on September 28, 2014

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