Weather on August 21

Glendale, AZ

55 Years of Data

Avg High
103°F
Avg Low
79°F
Warmest
2025
100°F avg
Coldest
1979
80°F avg

About This Date

August 21st in Glendale, AZ typically brings hot summer weather, with average highs around 103°F and lows near 79°F. Over 55 years of records, the warmest August 21st was in 2025 (100°F average), while the coldest was 1979 (80°F) — a 20°F range across recorded history. Rain or other precipitation has occurred on about 9% of August 21st dates historically, with the wettest August 21st recording 1.8" of rain. The last decade has been 2.1°F cooler on this date compared to 20-30 years ago.

The last decade has been 2.1°F cooler on this date compared to 20-30 years ago.

Planning for August 21st in Glendale, AZ? Stay hydrated and seek shade during peak afternoon hours.

Warming Trend
1.1°F per decade on this date
YearHighLowAvgPrecipSnow
2025warmest113°87°100°
2024112°85°98°
202389°72°80°
202295°73°84°1.5"
2021100°77°89°
2020100°81°90°
2019112°78°95°
2018102°87°95°
2017102°83°92°
201699°76°87°0.25"
2015105°83°94°
201498°74°86°0.05"
2013110°86°98°
2012104°83°93°
2011107°79°93°
2010107°86°97°
2009109°85°97°
2008106°78°92°
2007104°86°95°
2006108°85°96°
2005109°80°95°
2004101°76°88°
2003102°79°90°
2002102°76°89°
2001104°80°92°
2000107°81°94°
1999108°82°95°
1998105°85°95°
1997107°88°97°
1996106°87°96°
1995101°73°87°0.71"
1994107°82°95°
1993104°81°92°
1992104°83°93°
1991103°88°95°
1990100°75°88°
198999°78°88°
198895°74°84°1.8"
1987105°82°94°
1986111°87°99°
1985104°79°91°
198497°73°85°
198397°73°85°
1982101°82°91°
1981106°83°94°
1980103°65°84°
1979coldest100°61°80°
1978103°79°91°
1977101°80°90°
1976104°72°88°
1975100°69°85°
1974102°66°84°
1973104°75°90°
1972106°68°87°
197191°76°83°
55 years of data from ALHAMBRA

Browse Weather History

Weather data provided by NOAA Climate Data Online. Not for critical planning.

August 21st Weather in Glendale, AZ - 55 Years of History