Frost dates · USDA zone 5b

Frost dates for Rapid City, SD

Rapid City, SD sees its last 32 °F night of spring around May 3 and its first of fall around October 8 — a 157-day freeze-free season in a typical year.

May 3Last spring frostmedian · 1 in 10 years after May 17
Oct 8First fall frostmedian · 1 in 10 years before Sep 26
157Freeze-free daysmedian year · ≥137 in 9 of 10
5bUSDA zone2023 map · ZIP 57701
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Pick a sauce; the Plan Builder runs this station's dates and hands back the calendar, plant count and gear list.

Freeze odds, by date

OddsLast spring freeze afterFirst fall freeze before
9 years in 10Apr 20Oct 23
Median — 1 year in 2May 3Oct 8
1 year in 10May 17Sep 26

The top row is the risky edge: in 9 years of 10 a spring freeze still comes after it, so tender transplants set out then need cover. The bottom row is the cautious date — only 1 year in 10 freezes after it — and the one to plan uncovered tender transplants against. Freeze-free season: 157 days median, at least 137 in 9 years of 10, at least 176 days in 1 year of 10. NOAA ranks season length year by year, so it is not the gap between two rows above. A hard freeze (28 °F) has a median last date of Apr 22 and first of Oct 18.

Rapid City planting calendar, 2027

Every row runs from the median last frost (May 3) and median first frost (Oct 8) above, using each cultivar's days to maturity. Same engine as the Plan Builder.

CropStart indoorsTransplant / plantFirst harvestDays
Hardneck GarlicSiberian (porcelain hardneck)—Oct 15prior fallJun 12240 from sow
Spanish OnionYellow Sweet Spanish (long-day)Feb 8Apr 5Jul 24110 from transplant
Mustard greensGarnet Giant (Brassica juncea)Direct sowMay 3Jun 230 from sow
CilantroSlow Bolt (Coriandrum sativum)Apr 19Apr 19Jun 345 from sow
Genovese BasilGenoveseApr 5May 17Jul 1660 from transplant
CayenneLong Slim Cayenne (Capsicum annuum)Mar 8May 10Jul 2475 from transplant
HabaneroOrange Habanero (Capsicum chinense)Feb 22May 17Aug 2095 from transplant
JalapeñoEarly Jalapeño (Capsicum annuum)Mar 8May 10Jul 2475 from transplant
Marconi Red PepperMarconi Red (Capsicum annuum)Mar 8May 10Jul 2980 from transplant
SerranoSerrano Tampiqueño (Capsicum annuum)Mar 8May 10Jul 2980 from transplant
Nantes CarrotScarlet NantesApr 19Apr 19Jun 2870 from sow
TomatilloToma VerdeMar 22May 10Jul 1970 from transplant
Roma TomatoRoma VF (determinate paste)Mar 22May 10Jul 2475 from transplant
San Marzano TomatoSan Marzano (indeterminate paste)Mar 22May 10Jul 2980 from transplant

Tight means first harvest lands within two weeks of the median first fall frost: start that crop indoors on time or cover it in fall.

Rapid City frost questions

When is the last frost in Rapid City, SD?

The median last 32 °F freeze at RAPID CITY WFO, SD is May 3: half of years see a later one. One year in ten, a freeze still comes after May 17; nine years in ten, it comes after April 20. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.

When is the first frost in Rapid City, SD?

The median first 32 °F freeze of fall is October 8. One year in ten it arrives before September 26; nine years in ten, before October 23.

How long is the growing season in Rapid City, SD?

157 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 137 days; one year in ten, at least 176 days.

What growing zone is Rapid City, SD?

USDA hardiness zone 5b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 57701. A zone describes the coldest winter night, not when frost ends, so it is the wrong number for a planting calendar — the frost dates on this page are the right one.

When should I plant tomatoes in Rapid City, SD?

Start Roma VF (determinate paste) seeds indoors around Mar 22 and transplant around May 10, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for May 17. First ripe fruit lands around Jul 24.

When should I plant peppers in Rapid City, SD?

Sow jalapeño indoors on a heat mat around Mar 8; transplant no earlier than May 10, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jul 24.

Nearby in South Dakota

All South Dakota frost dates → · How frost-date math drives a sowing calendar →