Weather on August 21
Cambridge, MA
55 Years of Data
Avg High
80°F
Avg Low
59°F
Warmest
2003
81°F avg
Coldest
1984
56°F avg
About This Date
August 21st in Cambridge, MA typically brings warm summer weather, with average highs around 80°F and lows near 59°F. Over 55 years of records, the warmest August 21st was in 2003 (81°F average), while the coldest was 1984 (56°F) — a 25°F range across recorded history. Rain or other precipitation has occurred on about 25% of August 21st dates historically, with the wettest August 21st recording 4.57" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for August 21st in Cambridge, MA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.1°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 65° | 54° | 59° | 1.04" | — |
| 2024 | 71° | 53° | 62° | 0.13" | — |
| 2023 | 85° | 64° | 74° | — | — |
| 2022 | 94° | 68° | 81° | — | — |
| 2021 | 80° | 71° | 76° | — | — |
| 2020 | 82° | 59° | 71° | — | — |
| 2019 | 90° | 65° | 77° | — | — |
| 2018 | 78° | 64° | 71° | — | — |
| 2017 | 87° | 62° | 75° | — | — |
| 2016 | 90° | 61° | 75° | — | — |
| 2015 | 87° | 72° | 79° | 0.18" | — |
| 2014 | 72° | 60° | 66° | — | — |
| 2013 | 87° | 62° | 75° | — | — |
| 2012 | 81° | 60° | 70° | — | — |
| 2011 | 85° | 65° | 75° | — | — |
| 2010 | 86° | 54° | 70° | — | — |
| 2009 | 83° | 72° | 77° | 0.94" | — |
| 2008 | 73° | 53° | 63° | — | — |
| 2007 | 67° | 55° | 61° | — | — |
| 2006 | 77° | 62° | 70° | — | — |
| 2005 | 88° | 69° | 78° | 0.05" | — |
| 2004 | 79° | 63° | 71° | 2.67" | — |
| 2003warmest | 90° | 73° | 81° | — | — |
| 2002 | 77° | 61° | 69° | 0.25" | — |
| 2001 | 80° | 68° | 74° | 0.3" | — |
| 2000 | 73° | 50° | 62° | — | — |
| 1999 | 80° | 61° | 70° | — | — |
| 1998 | 78° | 52° | 65° | — | — |
| 1997 | — | 56° | — | 1.12" | — |
| 1996 | 83° | 59° | 71° | — | — |
| 1995 | 80° | 51° | 66° | — | — |
| 1994 | 82° | 64° | 73° | — | — |
| 1993 | 82° | 63° | 72° | 2.36" | — |
| 1992 | 75° | 51° | 63° | — | — |
| 1991 | 67° | 57° | 62° | 4.57" | — |
| 1990 | 70° | 66° | 68° | — | — |
| 1989 | 82° | 66° | 74° | — | — |
| 1988 | 82° | 54° | 68° | — | — |
| 1987 | 84° | 59° | 72° | 0.2" | — |
| 1986 | 76° | 56° | 66° | — | — |
| 1985 | 65° | 63° | 64° | — | — |
| 1984coldest | 77° | 36° | 56° | — | — |
| 1983 | 93° | 61° | 77° | — | — |
| 1982 | 80° | 60° | 70° | — | — |
| 1981 | — | 46° | — | — | — |
| 1980 | 64° | 58° | 61° | 0.28" | — |
| 1979 | 75° | 56° | 65° | 0.03" | — |
| 1978 | 85° | 66° | 75° | — | — |
| 1977 | 77° | 50° | 64° | — | — |
| 1976 | 86° | 59° | 73° | — | — |
| 1975 | 77° | 47° | 62° | — | — |
| 1974 | 84° | 59° | 72° | — | — |
| 1973 | 77° | 55° | 66° | — | — |
| 1972 | 76° | 43° | 59° | — | — |
| 1971 | 88° | 62° | 75° | — | — |
55 years of data from CHESTNUT HILL