Weather on March 18

San Marcos, CA

55 Years of Data

Avg High
71°F
Avg Low
48°F
Warmest
2026
73°F avg
Coldest
1979
48°F avg

About This Date

March 18th in San Marcos, CA typically brings pleasant spring weather, with average highs around 71°F and lows near 48°F. Over 56 years of records, the warmest March 18th was in 2026 (73°F average), while the coldest was 1979 (48°F) — a 25°F range across recorded history. Rain or other precipitation has occurred on about 21% of March 18th dates historically, with the wettest March 18th recording 3.91" of rain. Temperatures on this date have remained relatively stable over the past several decades.

Temperatures on this date have remained relatively stable over the past several decades.

Planning for March 18th in San Marcos, CA? Great weather for outdoor activities.

Warming Trend
0.9°F per decade on this date
YearHighLowAvgPrecipSnow
2026warmest84°62°73°
202567°50°58°
202476°49°62°0.1"
202380°46°63°
202280°49°64°
202170°44°57°
202059°44°52°0.66"
201979°50°64°
201863°45°54°
201783°54°68°
201676°55°65°
201576°59°67°
201478°57°68°
201369°53°61°
201254°42°48°1.68"
201169°45°57°
201065°53°59°
200972°50°61°0.03"
200865°46°55°
200766°51°59°
200656°49°52°0.1"
200565°53°59°
200480°49°64°
200368°43°55°
200261°40°50°1.19"
200182°48°65°
200082°47°64°
199969°42°56°
199873°55°64°
199789°49°69°
199675°51°63°
199571°57°64°
199478°57°68°
199373°56°64°
199268°64°66°
199168°43°55°
199079°45°62°
198976°46°61°
198879°47°63°
198767°44°55°
198673°41°57°0.03"
198564°46°55°0.05"
198479°44°61°
198360°50°55°2.54"
198256°43°49°3.91"
198174°42°58°
198070°43°56°0.2"
1979coldest57°40°48°0.15"
197872°54°63°
197762°37°50°
197670°43°56°
197572°39°55°
197470°53°61°
197364°46°55°
197269°57°63°
197179°45°62°
56 years of data from ESCONDIDO #2

Browse Weather History

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

March 18th Weather in San Marcos, CA - 55 Years of History