Weather on March 21

Santa Rosa, CA

55 Years of Data

Avg High
65°F
Avg Low
44°F
Warmest
2026
72°F avg
Coldest
1987
41°F avg

About This Date

March 21st in Santa Rosa, CA typically brings mild spring weather, with average highs around 65°F and lows near 44°F. Over 56 years of records, the warmest March 21st was in 2026 (72°F average), while the coldest was 1987 (41°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 23% of March 21st dates historically, with the wettest March 21st recording 4.06" of rain. The last decade has been 2.6°F cooler on this date compared to 20-30 years ago.

The last decade has been 2.6°F cooler on this date compared to 20-30 years ago.

Planning for March 21st in Santa Rosa, CA? Great weather for outdoor activities.

Warming Trend
0.7°F per decade on this date
YearHighLowAvgPrecipSnow
2026warmest91°53°72°
202565°41°53°
202468°47°57°
202356°42°49°2.84"
202277°44°61°
202169°36°52°
202069°38°53°
201965°37°51°
201862°52°57°2.51"
201762°52°57°
201656°45°50°
201569°50°60°
201465°40°52°
201365°41°53°
201268°49°58°
201160°36°48°
201066°42°54°
200969°47°58°0.23"
200868°35°52°
200772°42°57°
200658°41°49°
200561°50°55°0.51"
200469°51°60°
200369°44°57°
200263°44°53°
200165°49°57°
200080°56°68°
199960°48°54°0.05"
199859°54°56°0.18"
199778°55°67°
199668°43°55°
199555°43°49°1.45"
199460°42°51°
199366°48°57°
199264°47°55°
199159°42°51°0.05"
199071°44°58°
198969°49°59°
198871°47°59°
1987coldest49°34°41°1.83"
198665°41°53°
198563°41°52°
198466°43°54°
198360°40°50°0.64"
198264°33°49°
198152°43°47°1.68"
198067°41°54°
197965°42°53°
197869°48°59°
197776°38°57°
197675°36°55°
197556°39°47°4.06"
197460°50°55°
197354°41°47°1.02"
197266°46°56°
197171°37°54°
56 years of data from SANTA ROSA

Browse Weather History

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