Between 2011 and July 2020, Ballotpedia tracked 243 retirement announcements from members of the U.S. House and Senate. January saw the highest number of retirement announcements of any month at 45—31 during even-number years and 14 during odd-number years, when no regular congressional elections are held.
February and November had the second-highest total announcements at 27 each. Sixteen February announcements occurred during an election year and 11 during an off year. Most November announcements—24—took place during off years. The three November election year announcements were for the following election cycle.
The fewest retirements—eight—were announced in June. Six of those occurred during odd-number years. August and October saw the second-fewest announcements at 11 each. All of those except for one announcement occurred during off years.
As of August 26, 41 members of Congress—four U.S. senators and 37 U.S. representatives—are not running for re-election in 2020 (not including incumbents who resigned or otherwise left office early). In 2018, 55 members didn’t seek re-election. Forty-five members retired in 2016. In 2014, 48 members retired. And in 2012, 50 members retired.