When is the last frost in Cheyenne, WY?

The average last spring frost (50% probability of 32°F) in Cheyenne is around May 14, based on NOAA/NCEI 1991–2020 normals at the Cheyenne Wfo, WY station (7.1 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 Cheyenne?

The average first fall frost in Cheyenne, WY is around October 1, giving roughly a 139-day frost-free growing season.

What planting zone is Cheyenne, WY?

Cheyenne is in USDA plant hardiness zone 5b (average annual extreme minimum temperature -15 to -10°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Cheyenne?

In Cheyenne, WY the warmest month is July (avg high 83°F) and the coldest is February (avg low 17.8°F). It averages about 16″ of precipitation a year and 65.6″ of snow.

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Cheyenne, WY Planting Calendar & Frost Dates

USDA hardiness zone 5b · ZIP 82001 · elevation 1865′ · NOAA & USDA data

Cheyenne is in USDA hardiness zone 5b (winters can dip to -15 to -10°F), with a growing season of about 139 days between the average last spring frost (May 14) and first fall frost (October 1). The warmest month is July (avg high 83°F); the coldest is February (avg low 17.8°F). It averages 16″ of precipitation a year and 65.6″ 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 -15 to -10°F

Last spring frost

May 14

avg (50% prob, 32°F)

First fall frost

October 1

avg (50% prob, 32°F)

Growing season

139 days

frost-free window

Warmest month

July

avg high 83°F

Month-by-month typical weather in Cheyenne

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Cheyenne Wfo, WY (7.1 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	40.6	18	29.3	0.4	5.5
February	41.1	17.8	29.4	0.5	9.4
March	49.2	24.6	36.9	1	9.2
April	54.8	30.1	42.4	1.8	11.5
May	64.3	39.5	51.9	2.5	4
June	76.1	49	62.5	2.2	0
July	83	55.6	69.3	2.2	0
August	81.2	53.5	67.4	1.6	0
September	72.5	45.3	58.9	1.6	0.2
October	59	33.3	46.1	1.1	6.9
November	47.7	24.4	36.1	0.6	8
December	39.5	17.8	28.7	0.5	10.9

What to plant when in Cheyenne

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: April 2 · Transplant out: May 21
Peppers	warm	Start seeds indoors: March 19 · Transplant out: May 28
Cucumbers	warm	Direct sow: May 21
Zucchini / squash	warm	Direct sow: May 21
Bush beans	warm	Direct sow: May 21
Sweet corn	warm	Direct sow: May 21
Basil	warm	Transplant out: May 21
Peas	cool	Sow (spring): April 9 · Sow (fall): August 6
Spinach	cool	Sow (spring): April 2 · Sow (fall): August 6
Lettuce	cool	Sow (spring): April 16 · Sow (fall): August 6
Kale	cool	Transplant (spring): April 23 · Sow (fall): July 23
Broccoli	cool	Transplant (spring): April 30
Carrots	cool	Sow (spring): April 23 · Sow (fall): July 23
Onions	cool	Transplant (spring): April 16
Potatoes	cool	Plant seed potatoes: April 30
Radishes	cool	Sow (spring): April 16 · Sow (fall): August 20

Dates are computed from Cheyenne'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 Wyoming

Casper, WY

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 — Cheyenne Wfo, WY, 7.1 mi (confidence: high). Monthly weather normals: Cheyenne Wfo, WY, 7.1 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.