Weather on August 21

Concord, CA

55 Years of Data

Avg High
86°F
Avg Low
58°F
Warmest
2025
81°F avg
Coldest
1987
64°F avg

About This Date

August 21st in Concord, CA typically brings warm summer weather, with average highs around 86°F and lows near 58°F — a 28°F daily swing. Over 55 years of records, the warmest August 21st was in 2025 (81°F average), while the coldest was 1987 (64°F) — a 17°F range across recorded history. Rain or other precipitation has occurred on about 2% of August 21st dates historically. The last decade has been 1.7°F warmer on this date compared to 20-30 years ago.

The last decade has been 1.7°F warmer on this date compared to 20-30 years ago.

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

Warming Trend
0.4°F per decade on this date
YearHighLowAvgPrecipSnow
2025warmest101°62°81°
202487°61°74°
202381°66°73°
202284°60°72°
202172°59°65°
202096°64°80°
201994°62°78°
201872°58°65°
201777°63°70°
201686°58°72°
201583°60°71°
201487°60°74°
201382°57°70°
201289°55°72°
201181°59°70°
201072°57°64°
200999°56°77°
200885°62°73°
200797°62°79°
200683°55°69°
200585°56°70°
200477°59°68°
200377°63°70°0.48"
200284°57°71°
200179°55°67°
200090°57°73°
199995°59°77°
199883°58°70°
199786°59°73°
199689°59°74°
199592°59°75°
199481°57°69°
199390°59°74°
199292°59°75°
199184°53°69°
199086°59°73°
198976°55°65°
198879°50°64°
1987coldest82°47°64°
198689°50°70°
198585°56°70°
198484°56°70°
198383°55°69°
198298°63°80°
198192°59°75°
198087°53°70°
197982°58°70°
197882°51°67°
197792°51°71°
197682°61°71°
197585°54°69°
197496°53°75°
197385°56°70°
197292°56°74°
197184°58°71°
55 years of data from CONCORD BUCHANAN FLD

Browse Weather History

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

August 21st Weather in Concord, CA - 55 Years of History