When is the last frost in Commerce City, CO?

The average last spring frost (50% probability of 32°F) in Commerce City is around May 3, based on NOAA/NCEI 1991–2020 normals at the Brighton 3 Se, CO station (6.2 mi away). Half of years it falls outside that date, so wait 1–2 weeks past it before setting out frost-tender plants.

When is the first fall frost in Commerce City?

The average first fall frost in Commerce City, CO is around October 7, giving roughly a 155-day frost-free growing season.

What planting zone is Commerce City, CO?

Commerce City is in USDA plant hardiness zone 6a (average annual extreme minimum temperature -10 to -5°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Commerce City?

In Commerce City, CO the warmest month is July (avg high 90°F) and the coldest is January (avg low 16.1°F). It averages about 14.1″ of precipitation a year and 34.5″ of snow.

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Commerce City, CO Planting Calendar & Frost Dates

USDA hardiness zone 6a · ZIP 80022 · elevation 1529′ · NOAA & USDA data

Commerce City is in USDA hardiness zone 6a (winters can dip to -10 to -5°F), with a growing season of about 155 days between the average last spring frost (May 3) and first fall frost (October 7). The warmest month is July (avg high 90°F); the coldest is January (avg low 16.1°F). It averages 14.1″ of precipitation a year and 34.5″ of snow, mostly mid-winter. Start cool-season crops several weeks before the last frost; wait until after it for tomatoes, peppers and other tender crops.

Hardiness zone

min temp -10 to -5°F

Last spring frost

May 3

avg (50% prob, 32°F)

First fall frost

October 7

avg (50% prob, 32°F)

Growing season

155 days

frost-free window

Warmest month

July

avg high 90°F

Month-by-month typical weather in Commerce City

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Brighton 3 Se, CO (6.2 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	44.4	16.1	30.2	0.4	5.2
February	45.9	18.5	32.2	0.4	5.3
March	55.9	26.7	41.3	1	6
April	62.9	33.9	48.4	1.8	3.1
May	71.9	43.2	57.5	2.4	0.5
June	84.1	52.4	68.3	1.4	0
July	90	58.2	74.1	1.7	0
August	87.6	56.4	72	1.8	0
September	79.8	47.4	63.6	1.2	0.2
October	65.9	35	50.4	1	3.2
November	53.3	25	39.1	0.7	5.8
December	44	16.3	30.2	0.4	5.2

What to plant when in Commerce City

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: March 22 · Transplant out: May 10
Peppers	warm	Start seeds indoors: March 8 · Transplant out: May 17
Cucumbers	warm	Direct sow: May 10
Zucchini / squash	warm	Direct sow: May 10
Bush beans	warm	Direct sow: May 10
Sweet corn	warm	Direct sow: May 10
Basil	warm	Transplant out: May 10
Peas	cool	Sow (spring): March 29 · Sow (fall): August 12
Spinach	cool	Sow (spring): March 22 · Sow (fall): August 12
Lettuce	cool	Sow (spring): April 5 · Sow (fall): August 12
Kale	cool	Transplant (spring): April 12 · Sow (fall): July 29
Broccoli	cool	Transplant (spring): April 19
Carrots	cool	Sow (spring): April 12 · Sow (fall): July 29
Onions	cool	Transplant (spring): April 5
Potatoes	cool	Plant seed potatoes: April 19
Radishes	cool	Sow (spring): April 5 · Sow (fall): August 26

Dates are computed from Commerce City's average frost dates using standard cool-/warm-season timing. They're a starting point — a cold spring, a warm microclimate, or a fast-maturing variety can shift them by a week or two.

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Gear that helps you plant on time

Some links below are Amazon affiliate links (tag theboringthin-20). If you buy through them we may earn a small commission at no extra cost to you — it keeps this almanac free. We only list generic, genuinely-useful categories.

Soil thermometer →Know when the ground is warm enough to sow — the honest signal, not the calendar.Seed-starting trays + dome →Start tomatoes & peppers indoors on the schedule below.Seedling heat mat →Warms the soil for faster, more even germination indoors.Floating row cover / frost cloth →Buys you 4–8°F to beat an early or late frost.Raised garden bed kit →Warms and drains faster in spring than in-ground soil.Garden gloves →Basic kit for transplant day.

Nearby cities in Colorado

Aurora, CO Thornton, CO Westminster, CO Denver, CO Broomfield, CO Arvada, CO Littleton, CO Boulder, CO

Sources & method. Hardiness zone: 2023 USDA Plant Hardiness Zone Map (PRISM Climate Group, Oregon State University). Frost dates & growing season: NOAA/NCEI 1991–2020 U.S. Climate Normals, nearest station with published freeze normals — Brighton 3 Se, CO, 6.2 mi (confidence: high). Monthly weather normals: Brighton 3 Se, CO, 6.2 mi (confidence: high). ZIP centroid from U.S. Census 2023 ZCTA data. Frost dates are the 50%-probability date — half of years frost occurs outside the stated date. Nothing here is invented; where the nearest station is far, we say so. Last updated 2026-07-22.