Skip to content

Planting zones · Denver, Colorado

What Planting Zone Is Denver?

Denver is in USDA zone 6a. Semi-arid Front Range city at about 5,200 ft. Precipitation is light (about 16 in. a year) and peaks in May, and the median frost dates are October 12 and April 30.

  • USDA zone (2023)6a
  • Coldest night (avg.)-10 to -5°FZIP 80202
  • Median last frostApr 3032°F
  • Median first frostOct 1232°F
  • Annual precipitation16 inches
  • Frost-free season165 days

Denver hardiness zone by ZIP code

On the 2023 USDA Plant Hardiness Zone Map, the ZIP codes we sampled in Denver fall in zone 6a; 80202 (zone 6a) has an average annual extreme minimum of -10 to -5°F. Choose perennials, shrubs, and trees rated at least to zone 6.

2023 USDA zone for sampled Denver ZIP codes
ZIPZoneAvg. coldest night
800136a-10 to -5°F
800316a-10 to -5°F
801236a-10 to -5°F
802026a-10 to -5°F
802206a-10 to -5°F
802366a-10 to -5°F

Not listed? Look up any ZIP code.

Frost dates and when to plant

The median last spring frost (32°F) at Denver Water Dept. (downtown) is Apr 30 and the median first fall frost is Oct 12, a typical frost-free season of about 165 days.

Plant container perennials and shrubs after the median last frost (Apr 30), or in early fall at least six weeks before the median first frost (Oct 12) so roots can settle in before the ground freezes.

Rainfall and heat in Denver

Average annual precipitation is 16 inches (Denver Water Dept. (downtown), 1991–2020), spread across the year with May the wettest month and January the driest.

The average high in July is about 91°F and the average low in December is about 21°F, measured at about 5,230 ft.

That is why a zone rating alone isn't enough for a xeriscape here: pick plants that are both cold-hardy to zone 6 and rated very low or low water once established.

Low-water plants for Denver

72 plants in our database are hardy to zone 6 and suited to zone 6. Here are 12, driest first, across plant types.

See all zone 6 plants

Frequently asked questions

What planting zone is Denver?

Denver, CO is in USDA hardiness zone 6a on the 2023 USDA Plant Hardiness Zone Map, based on the ZIP codes we sampled (80013: 6a, 80031: 6a, 80123: 6a, 80202: 6a, 80220: 6a, 80236: 6a). In 80202, the average coldest night of the year is -10 to -5°F.

When is the last frost in Denver?

The median last spring frost (32°F) at Denver Water Dept. (downtown) is Apr 30 and the median first fall frost is Oct 12, a typical frost-free season of about 165 days.

How much rain does Denver get?

Average annual precipitation is 16 inches (Denver Water Dept. (downtown), 1991–2020), spread across the year with May the wettest month and January the driest.

Sources

  1. NOAA NCEI U.S. Climate Normals 1991–2020, Denver Water Dept. (downtown) (USC00052223). ncei.noaa.gov
  2. USDA ARS 2023 Plant Hardiness Zone Map, by ZIP. planthardiness.ars.usda.gov