Evans, CO planting zone & frost dates

Evans is in USDA hardiness zone 5b. The last spring frost usually comes around May 2 and the first fall frost around October 8, for a growing season of about 159 days.

USDA hardiness zone5bavg. extreme winter low -15°F to -10°F

Average last spring frostMay 290% chance of no frost after May 14

Average first fall frostOctober 810% chance of frost by September 26

Growing season159 daysfrost-free days in an average year

Planting calendar for Evans

Dates are counted from the average last spring frost (May 2) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.

Crop	When
Tomatoes	Start seeds indoors: Mar 7 – Mar 21 Transplant outdoors: May 9 – May 16
Peppers	Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: May 16 – May 23
Eggplant	Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: May 16 – May 23
Broccoli	Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: Apr 4 – Apr 18
Cabbage	Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: Apr 4 – Apr 18
Onions (sets)	Plant outdoors: Apr 4 – Apr 18
Peas	Sow outdoors: Mar 21 – Apr 4
Spinach	Sow outdoors: Mar 21 – Apr 4
Lettuce	Sow outdoors: Apr 4 – Apr 18
Carrots	Sow outdoors: Apr 4 – Apr 18
Potatoes	Plant outdoors: Apr 4 – Apr 18
Beans	Sow outdoors: May 9 – May 16
Sweet corn	Sow outdoors: May 9 – May 16
Cucumbers	Sow outdoors: May 9 – May 16
Squash & zucchini	Sow outdoors: May 9 – May 16
Basil	Start seeds indoors: Mar 21 – Apr 4 Transplant outdoors: May 9 – May 16

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 13 (8 weeks before the average first fall frost on Oct 8).

Frost risk in detail

	90% chance	50% chance	10% chance
Last 32°F frost in spring is after	Apr 17	May 2	May 14
First 32°F frost in fall is before	Oct 21	Oct 8	Sep 26

How to read it: in spring there is a 10% chance of a frost after May 14, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 26. A hard freeze (28°F) usually ends around April 20.

Hardiness zone by ZIP code in Evans

80620 zone 5b

Nearby cities

Greeley zone 5b, last frost May 2
Johnstown zone 5b, last frost May 10
Windsor zone 5b, last frost May 3
Firestone zone 5b, last frost May 7
Frederick zone 5b, last frost May 7
Loveland zone 5b, last frost May 10
Brighton zone 5b, last frost May 3
Fort Collins zone 5b, last frost May 2

All cities in Colorado → · Other zone 5b cities →

Questions

What growing zone is Evans, CO?

Evans is in USDA Plant Hardiness Zone 5b (average extreme winter low -15°F to -10°F), according to the USDA 2023 map.

When is the last frost in Evans?

The average last spring frost (32°F) in Evans is May 2. There is still a 10% chance of frost until May 14.

When can I plant tomatoes in Evans?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 9 – May 16. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Greeley Unc, CO (USC00053553), 2.9 km (1.8 mi) from the city center, elevation 1437 m, based on 25 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.