Analysis of Back-to-Back Days With Identical High & Low Temperatures

 

 

In the years I've spent poring over New York's daily weather data, I'd take note of pairs of days with the same high and low.  This analysis is the product of my curiosity about how common such pairings are.  On average, two occur each year (2.3 to be exact).  The most has been ten, which happened in 1931 and 2010.  There have been ten years with five or more pairs, including 2020.  Thirteen years have had none, most recently in 2022.  (Of course, if temperatures were reported to one decimal place, these type of days would be even rarer than they already are.)  Here are some more interesting findings:

 

• There have been three streaks that had three consecutive days with identical highs/lows - in 1988 (Aug. 3-5, all with a high/low of 89°/76°); 1984 (May 5-7, highs/lows of 69°/53°), and 1879 (May 8-10, 69°/49°).  And during the summer of 2013, after a high/low of 83°/67° on July 30-31, there was another day with the same high/low two days later, on Aug. 2.

• There have been 23 pairs that missed by one degree of having a third consecutive day with the same high/low.  The most recent occurrence was in December 2010, when 12/7 had a high/low of 36°/30° after a high/low of 35°/30° on 12/5 and 12/6.  And each of the streaks of three-days (mentioned above) narrowly missed being four-day streaks:
  • Aug. 3-5, 1988's streak missed being a four-day streak when the high/low on Aug. 6  was 89°/75° instead of 89°/76°.
  • May 5-7, 1984's streak of 69°/53° was followed on May 8 by a high/low of 69°/55°.
  • The day before 1879's streak of May 8-10, with highs/lows of 69°/49°, the high/low was 70°/50°.

• There have been three back-to-back pairs of days: July 28-31, 2010 (89°/74° on 7/28-29 and 85°/66° on 7/30-31); March 3-6, 1952 (pairs of 36°/32° and 42°/31°); and Aug. 17-20, 1906 (pairs of 85°/71° and 87°/77°).  And there has been one instance of three consecutive pairs of days: Dec. 16-21, 1901 (26°/20° on Dec. 16-17; 28°/20° on Dec. 18-19; and 26°/19° on Dec. 20-21).  (March 1952's and August 1906's streaks narrowly missed having three consecutive pairs.)

• Of the 13 years with no pair of days, only two occurred after 1956 - 2000 and 2022.  The other years: 1956, 1954, 1943, 1934, 1930 1924, 1916, 1903, 1889, 1881 and 1869.

• There have been two instances of back-to-back years having the same pair of dates with the same high/low.  It first occurred on July 27-28, in 1897 and 1898.  (The pair of highs/lows in 1897 was 67°/64°, and 80°/74° in 1898.)  The second time was in 2020 and 2021 on May 29-30 (highs and lows of these pair were 81°/67° and 51°/47°, respectively).  And there have been five instances of pairs of the same dates being two years apart, most recently in 2018, when it and 2016 each had a pair of days on Dec 23-24.

• July 27-28 has had the same high/low in seven years, the most of any pair of dates: 2023, 2007, 1988, 1939, 1910, 1898, and 1897.

• May 18-19, 1932 and May 18-19, 2005 had the same pairs of highs/lows (70°/53°).

• There have been four pairs of 85°/70° highs/lows, which is the most frequent of any pair  (occurring on July 4-5, 2017; May 27-28, 2015; June 25-26 2014; and June 27-28, 1994).

• July and August are the months most likely to have seen pairs of days with the same high/low (48 and 51 occurrences,respectively); February and October are the months least likely to report a pair of these days (with just 12 each). 

• Hottest pair: 100°/79° on July 9-10, 1937; Coldest pair: 23°/14° on Jan. 28-29, 1986.