Hottest Day of the Year in Bowling Green, KY

The hottest day of the year where I live can vary by more than three months. 

Since 1948, it's been as early as June 1 (in 1951) and as late as September 23 (in 1961). 

June 1-15: 6 times
June 16-30: 7 times
July 1-15: 14 times
July 16-31: 16 times
Aug. 1-15: 12 times
Aug. 16-31: 9 times
Sept. 1-15: 5 times
Sept. 16-30: 1 time

The average date is July 24, though it's been shifting later. The record period is 69 years, so I divided it up into three 23-year intervals.

1948-1970: July 23
1971-1993: July 22
1994-2016: July 29

The average temperature is a toasty 97.52 F / 36.40 C on the hottest day of the year, but the hottest day of 2012 (June 29) was an amazing 109 F / 43 C! 2004's hottest day, on the other hand, was just 91 F / 33 C. 

91-93 F: 10 times
94-96 F: 16 times
97-99 F: 28 times
100-102 F: 7 times
103-105 F: 4 times (all 103)
106-109 F: 4 times

There is no real trend of it getting hotter or colder over time.

1948-1970: 97.65 F
1971-1993: 97.17 F
1994-2016: 97.74 F

Bowling Green, KY data used 1948-1954, 1973-2000, 2002-present.
Nashville, TN data used 1955-1972 and 2001 due to a lack of Bowling Green data for those years.

Season Lengths in Nashville, TN: Part 1, 1959-1963

I've decided to try a little experiment. Where I live, it feels like summer when temperatures average >22 C / 72 F and winter when they average <8 C / 46 F. This also gives us (roughly) a 3.5 month summer and 3 month winter, which makes sense because we do tend to get a bit of seasonal lag in September. 

I've used a 21-day running average (the day, 10 days prior, and 10 days after) to determine when each season began and ended. For instance, the temperature for November 5, 2014 was 49.8, taking the means of all days from October 26 - November 15. 

If the temperature dropped below 46 and stayed there, or fell below 46 and stayed there longer than any late fall >46 spells, I called it winter. For instance, in 2014, it was below 46 from Nov. 8 - 28 and above 46 from Nov. 29 - Dec. 2 before falling below 46 for the rest of the winter. Therefore, I called anything from November 8 winter. Ditto for summer, but with 72. For spring, replace "fell below" with "rose above" and "late fall >46" with "late winter <46"

On average:
Winter: November 26 - March 1
Spring: March 2 - May 31
Summer: June 1 - September 15
Fall: September 16 - November 25

Update to my original Sept. 20, 2016 post. I've decided to do every season from 1959-present in Nashville. I will also probably make a blog in the near future detailing all of my weather musings and interesting statistics. 

This is the first release, Dec. 4, 1958 - Nov. 28, 1963. 

Winter 1958-59: ? - March 13 (Peak: December 16, 31.9 F)
Spring 1959: March 14 - May 27
Summer 1959: May 28 - October 2 (Peak: August 23, 80.4 F)
Fall 1959: October 3 - November 14
Winter 1959-60: November 15 - March 24 (Peak: February 28, 27.8 F)
Spring 1960: March 25 - May 24
Summer 1960: May 25 - September 16 (Peak: July 30, 81.1 F)
Fall 1960: September 17 - November 27
Winter 1960-61: November 28 - February 11 (Peak: January 29, 28.9 F)
Spring 1961: February 12 - June 26
Summer 1961: June 27 - September 17 (Peak: July 24, 79.9 F)
Fall 1961: September 18 - December 3
Winter 1961-62: December 4 - March 17 (Peak: January 7, 29.9 F)
Spring 1962: March 18 - May 6
Summer 1962: May 7 - September 12 (Peak: August 14, 80.2 F)
Fall 1962: September 13 - November 27
Winter 1962-63: November 28 - March 4 (Peak: January 22, 25.6 F)
Spring 1963: March 5 - June 1
Summer 1963: June 2 - September 13 (Peak: July 29, 79.5 F)
Fall 1963: September 14 - November 28