Weather on August 21
Hayward, CA
55 Years of Data
Avg High
75°F
Avg Low
57°F
Warmest
2020
73°F avg
Coldest
1994
60°F avg
About This Date
August 21st in Hayward, CA typically brings pleasant summer weather, with average highs around 75°F and lows near 57°F. Over 52 years of records, the warmest August 21st was in 2020 (73°F average), while the coldest was 1994 (60°F) — a 13°F range across recorded history. Rain or other precipitation has occurred on about 2% of August 21st dates historically. The last decade has been 2.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.8°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Hayward, CA? Great weather for outdoor activities.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 85° | 59° | 72° | — | — |
| 2024 | 75° | 62° | 69° | — | — |
| 2023 | 78° | 64° | 71° | 0.08" | — |
| 2022 | 77° | 56° | 66° | — | — |
| 2021 | 71° | 60° | 66° | — | — |
| 2020warmest | 83° | 64° | 73° | — | — |
| 2019 | 79° | 60° | 69° | — | — |
| 2018 | 71° | 59° | 65° | — | — |
| 2017 | 76° | 61° | 68° | — | — |
| 2016 | 72° | 60° | 66° | — | — |
| 2015 | 70° | 61° | 65° | — | — |
| 2014 | 79° | 63° | 71° | — | — |
| 2013 | 72° | 57° | 64° | — | — |
| 2012 | 70° | 55° | 62° | — | — |
| 2011 | 69° | 59° | 64° | — | — |
| 2010 | 64° | 57° | 61° | — | — |
| 2009 | 83° | 58° | 70° | — | — |
| 2008 | 72° | 61° | 66° | — | — |
| 2007 | 80° | 61° | 70° | — | — |
| 2006 | 69° | 55° | 62° | — | — |
| 2005 | 66° | 56° | 61° | — | — |
| 2004 | 72° | 62° | 67° | — | — |
| 2003 | 75° | 64° | 70° | — | — |
| 2002 | 69° | 56° | 62° | — | — |
| 2001 | 67° | 55° | 61° | — | — |
| 2000 | 76° | 56° | 66° | — | — |
| 1999 | 81° | 59° | 70° | — | — |
| 1998 | 77° | 54° | 65° | — | — |
| 1997 | 81° | 55° | 68° | — | — |
| 1996 | 81° | 53° | 67° | — | — |
| 1995 | 71° | 54° | 62° | — | — |
| 1994coldest | 66° | 53° | 60° | — | — |
| 1993 | 82° | 57° | 70° | — | — |
| 1989 | 73° | 56° | 64° | — | — |
| 1988 | 70° | 57° | 63° | — | — |
| 1987 | 73° | 54° | 63° | — | — |
| 1986 | 74° | 53° | 63° | — | — |
| 1985 | 71° | 56° | 63° | — | — |
| 1984 | 75° | 56° | 65° | — | — |
| 1983 | 75° | 58° | 66° | — | — |
| 1982 | 76° | 53° | 64° | — | — |
| 1981 | 75° | 56° | 65° | — | — |
| 1980 | 75° | 54° | 64° | — | — |
| 1979 | 75° | 58° | 66° | — | — |
| 1978 | 76° | 53° | 64° | — | — |
| 1977 | 68° | 55° | 62° | — | — |
| 1976 | 82° | 59° | 71° | — | — |
| 1975 | 78° | 50° | 64° | — | — |
| 1974 | 85° | 51° | 68° | — | — |
| 1973 | 79° | 46° | 62° | — | — |
| 1972 | 77° | 57° | 67° | — | — |
| 1971 | 71° | 54° | 62° | — | — |
52 years of data from HAYWARD AIR TERMINAL