Weather on August 21 at Grand Canyon
Grand Canyon National Park
Based on 55 years of data from Flagstaff, AZ
Elevation Note: Grand Canyon sits at 7,000 ft. Expect temperatures 25°F cooler than the data shown below, which comes from Flagstaff, AZ at a lower elevation.
Planning Your Visit
August 21st in Grand Canyon National Park (via Flagstaff, AZ) typically brings pleasant summer weather, with average highs around 78°F and lows near 49°F — a 29°F daily swing. Over 55 years of records, the warmest August 21st was in 2025 (72°F average), while the coldest was 1979 (53°F) — a 19°F range across recorded history. Rain or other precipitation has occurred on about 40% of August 21st dates historically, with the wettest August 21st recording 1.57" of rain. The last decade has been 3.2°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.2°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Grand Canyon? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 88°F | 56°F | 0.23" | 0" |
| 2024 | 82°F | 56°F | 1.57" | 0" |
| 2023 | 72°F | 58°F | 0.1" | 0" |
| 2022 | 79°F | 52°F | 0.51" | 0" |
| 2021 | 73°F | 45°F | 0" | 0" |
| 2020 | 84°F | 55°F | 0.13" | 0" |
| 2019 | 87°F | 49°F | 0" | 0" |
| 2018 | 75°F | 55°F | 0.28" | 0" |
| 2017 | 76°F | 53°F | 0" | 0" |
| 2016 | 72°F | 48°F | 0" | 0" |
| 2015 | 78°F | 49°F | 0" | 0" |
| 2014 | 68°F | 46°F | 0.71" | 0" |
| 2013 | 73°F | 57°F | 0.53" | 0" |
| 2012 | 76°F | 57°F | 1.02" | 0" |
| 2011 | 81°F | 50°F | 0" | 0" |
| 2010 | 84°F | 50°F | 0" | 0" |
| 2009 | 90°F | 46°F | 0" | 0" |
| 2008 | 81°F | 46°F | 0" | 0" |
| 2007 | 86°F | 54°F | 0" | 0" |
| 2006 | 82°F | 50°F | 0" | 0" |
| 2005 | 79°F | 45°F | 0" | 0" |
| 2004 | 74°F | 49°F | 0.05" | 0" |
| 2003 | 75°F | 54°F | 0.05" | -- |
| 2002 | 76°F | 47°F | 0" | 0" |
| 2001 | 75°F | 48°F | 0" | -- |
| 2000 | 76°F | 47°F | 0.18" | 0" |
| 1999 | 80°F | 47°F | 0.1" | -- |
| 1998 | 77°F | 50°F | 0.36" | -- |
| 1997 | 77°F | 54°F | 0.23" | -- |
| 1996 | 76°F | 48°F | 0" | -- |
| 1995 | 74°F | 52°F | 0.69" | 0" |
| 1994 | 79°F | 48°F | 0" | 0" |
| 1993 | 76°F | 52°F | 0.15" | 0" |
| 1992 | 74°F | 54°F | 0" | 0" |
| 1991 | 90°F | 50°F | 0" | 0" |
| 1990 | 77°F | 38°F | 0" | 0" |
| 1989 | 74°F | 41°F | 0" | 0" |
| 1988 | 70°F | 56°F | 1.4" | 0" |
| 1987 | 81°F | 48°F | 0" | 0" |
| 1986 | 85°F | 51°F | 0" | 0" |
| 1985 | 81°F | 46°F | 0" | 0" |
| 1984 | 72°F | 45°F | 0" | 0" |
| 1983 | 74°F | 42°F | 0" | 0" |
| 1982 | 77°F | 57°F | 0" | 0" |
| 1981 | 82°F | 55°F | 0" | 0" |
| 1980 | 85°F | 42°F | 0" | 0" |
| 1979 | 73°F | 33°F | 0" | 0" |
| 1978 | 81°F | 48°F | 0.13" | 0" |
| 1977 | 82°F | 54°F | 0" | 0" |
| 1976 | 83°F | 48°F | 0.03" | 0" |
| 1975 | 78°F | 47°F | 0.13" | 0" |
| 1974 | 80°F | 43°F | 0" | 0" |
| 1973 | 79°F | 48°F | 0" | 0" |
| 1972 | 83°F | 41°F | 0" | 0" |
| 1971 | 70°F | 50°F | 0.1" | 0" |