Weather on March 21 at Great Sand Dunes

Great Sand Dunes National Park and Preserve

CORocky Mountain8,200 ft elevation
Avg High55°F
Avg Low18°F
Warmest202652°F
Coldest198324°F

Based on 56 years of data from Alamosa, CO

Elevation Note: Great Sand Dunes sits at 8,200 ft. Expect temperatures 29°F cooler than the data shown below, which comes from Alamosa, CO at a lower elevation.

Planning Your Visit

March 21st in Great Sand Dunes National Park (via Alamosa, CO) typically brings cool spring weather, with average highs around 55°F and lows near 18°F — a 37°F daily swing. Over 56 years of records, the warmest March 21st was in 2026 (52°F average), while the coldest was 1983 (24°F) — a 28°F range across recorded history. Precipitation has occurred on 7% of recorded March 21st dates, with snow falling 7% of the time (heaviest snowfall: 1.6"). The last decade has been 1.3°F cooler on this date compared to 20-30 years ago.

The last decade has been 1.3°F cooler on this date compared to 20-30 years ago.

Planning for March 21st in Great Sand Dunes? Bring layers as temperatures can vary throughout the day.

Year by Year History

YearHighLowPrecipSnow
202683°F22°F0"0"
202551°F2°F0"0"
202457°F20°F0"0"
202344°F22°F0"0"
202257°F21°F0"0"
202163°F23°F0"0"
202048°F18°F0"0"
201954°F17°F0"0"
201848°F10°F0"0"
201769°F28°F0"0"
201657°F19°F0"0"
201556°F28°F0"0"
201461°F18°F0"0"
201355°F17°F0"0"
201246°F5°F0"--
201159°F20°F0"--
201037°F10°F0"0"
200966°F22°F0"0"
200857°F21°F0"0"
200760°F33°F0"0"
200643°F6°F0.38"1.6"
200545°F19°F0"0"
200470°F23°F0"0"
200339°F29°F0.33"0.2"
200262°F9°F0"0"
200166°F22°F0"0"
200045°F24°F0"0"
199964°F28°F0"0"
199855°F18°F0"0"
199772°F20°F0"0"
199662°F13°F0"0"
199567°F32°F0"0"
199459°F17°F0"0"
199359°F25°F0"0"
199245°F13°F0"0"
199141°F21°F0"0"
199065°F22°F0"0"
198952°F5°F0"0"
198865°F14°F0"0"
198748°F12°F0"0"
198657°F16°F0"0"
198554°F17°F0"0"
198459°F20°F0"0"
198340°F9°F0"0"
198244°F5°F0"0"
198146°F17°F0"0"
198057°F10°F0"0"
197943°F27°F0.25"1"
197863°F11°F0"0"
197750°F12°F0"0"
197648°F3°F0"0"
197552°F30°F0"0"
197451°F10°F0"0"
197343°F23°F0.05"0.6"
197263°F14°F0"0"
197159°F10°F0"0"

March 21 at Nearby Parks

Holiday Weather at Great Sand Dunes

Official NPS WebsiteVisit nps.gov/grsa for park information, alerts, and reservations

Explore More at Great Sand Dunes

See historical weather for other dates

Back to Great Sand Dunes