Despite what the headline suggests, this post isn't about people obsessed with 1970s pop culture. Rather, it's a discussion about days that have had both their high and low temperatures in the 70s. These type of days occur infrequently - about once or twice each year. 33 years (since 1869) have never registered such a day, 53 have had one instance; the most days in one year was ten, which happened in 1905. In 2017 and 2018 there were five occurrences, joining just ten other years that had five or more (see chart below). Temperatures stuck in the 70s usually occur when tropical air is in place, the day is hazy/overcast, and rain is in the air.
- The warmest low in the 70s to be accompanied by a high temperature below 80° is 74°, which has happened three times - first in August 1901, then in August 1973, and very recently in July 2023. The first two had a high of 79°; in 2023 the high was 78°. (For reference, the average high when lows are between 70°-74° is around 86°).
- The most consecutive days with temperatures in the 70s all day is five, in 1905 (Aug. 30-Sept. 3).
- The most consecutive years without any "all-70" days is four, from 1962 to 1965 (and six out of seven years from 1962 to 1968). By contrast, there were 21 of these days in the three-year period 1905, 1906 and 1907; they had ten, five and six of these days, respectively.
- The first decade of the 20th century had more "stuck in the 70s" days than the next three decades combined (38 vs. 37). The 1890s had the second greatest number - 34. The decade that just ended, i.e., the 2010s, had 26 occurrences.
- The latest occurrences for a high/low in the 70s were in 2017, on Oct. 8 and 9 (at the time, the 9th was the latest date for a low in the 70s - until the following year). The earliest occurrences were on June 4 and 5 in 1960.
- The dates most likely to have experienced a day entirely in the 70s are: 7/23, 7/29, 8/9, and 8/12 - all of which have had seven such occurrences.
- One out of four of these days either had no measurable rain (half were before 1935), while another one out of four received more than a half-inch of rain. The greatest rainfall was in 1990, when 4.64" fell on Aug. 10 (the high/low was 76°/70°). Four other days with substantial rainfall were associated with Hurricanes Connie and Irene, in Aug. 1955 (2.70") and Aug. 2011 (2.88"), respectively, and tropical storms Fay in July 2020 (2.54") and Henri in Aug. 2021 (2.67").