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USDA Hardiness Zone 5b

Frost Dates for 81252 — Westcliffe, Colorado

NOAA 1991–2020 normals from Westcliffe, CO (7,873 ft), under a mile west.

Updated

In Westcliffe, the last spring frost (32°F) is around June 11 in half of years and has passed by June 28 in nine years out of ten. The first fall frost comes around September 9, as early as August 28 one year in ten, leaving a typical freeze-free season of 89 days (NOAA, Westcliffe, CO).

Last spring frost
June 11

50% probability

First fall frost
September 9

50% probability

Growing season
89 days

freeze-free, 50%

Hardiness zone
5b

-15 to -10°F (-26.1 to -23.3°C) coldest night

First snow
October 15

median, 1991–2020

Last snow
May 2

median, 1991–2020

Winters with snow
100%

28 of 28 observed

Snow per year
84.3"

NOAA normal

Frost risk by date in Westcliffe

Half of springs at Westcliffe, CO see their last 32°F night by June 11; only one in ten is past it by May 29, and one in ten still has one after June 28. Planting tender crops after June 18 leaves a 30% risk of a frost on them, after June 23 20%, and after June 28 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 85% of the 110 Colorado stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 9 in half of years, as early as August 28 one year in ten, and holds off past September 23 one year in ten. A hard freeze of 28°F follows 11 days later, around September 20; in spring the one-in-ten date for 28°F is June 13, 15 days before the 32°F one. The freeze-free season lasts 89 days in a typical year, shorter than at 91% of the 110 Colorado stations; it reaches 108 days one year in ten and falls short of 68 one year in ten. On average 213 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between October 13 and April 24.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°Ftoo rare for a date
32°FMay 29Jun 2Jun 4Jun 7Jun 11Jun 14Jun 18Jun 23Jun 28
28°FMay 16May 19May 22May 24May 28May 31Jun 3Jun 7Jun 13
24°FMay 3May 6May 9May 11May 14May 16May 19May 23May 30
20°FApr 20Apr 25Apr 28May 1May 3May 6May 8May 10May 15
16°FApr 8Apr 14Apr 18Apr 20Apr 24Apr 26Apr 30May 3May 7
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°Ftoo rare for a date
32°FAug 28Sep 1Sep 4Sep 6Sep 9Sep 11Sep 14Sep 18Sep 23
28°FSep 6Sep 10Sep 13Sep 17Sep 20Sep 23Sep 26Sep 29Oct 2
24°FSep 16Sep 20Sep 24Sep 26Sep 29Oct 1Oct 3Oct 6Oct 10
20°FSep 24Sep 29Oct 1Oct 3Oct 6Oct 8Oct 11Oct 14Oct 19
16°FSep 30Oct 4Oct 7Oct 11Oct 13Oct 16Oct 19Oct 22Oct 28

Freeze probabilities 1991–2020 at Westcliffe, CO, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.

Frost risk on any date in 81252 →Compare Westcliffe with another place →

Weather by month in Westcliffe

July is the warmest month at Westcliffe, CO, averaging 81°F by day and 45°F at night; December is the coldest at 40°F and 8°F. A freezing night is all but certain in every month from September to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 82% of years.

Warmth for growing adds up to 1,279 growing degree days a year (base 50°F), fewer than at 84% of the 110 Colorado stations. 28% of them (354) have built up by the end of June, and July adds the most, 395. Precipitation totals 13.8 inches a year, most in July (2.7") and least in January (0.5"); May to September bring 57% of it.

Monthly normals 1991–2020 at Westcliffe, CO
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan4080.5100%300
Feb42120.6100%270
Mar50201.1100%281
Apr56261.6100%2311
May66331.4100%1376
Jun77410.882%2266
Jul81452.76%<1395
Aug78442.016%<1343
Sep72370.997%8163
Oct61261.0100%2322
Nov49170.7100%282
Dec4080.5100%300

Monthly normals 1991–2020 at Westcliffe, CO (7,873 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.

Compared with the next station

The nearest other station, Canon City, CO, 26 miles northeast of Westcliffe and 2,495 feet lower, has a last frost 38 days earlier (May 4), a first frost 28 days later (October 7), a season 64 days longer.

Frost dates for 81212 (Canon City) →

When it snows in Westcliffe, Colorado

The first measurable snow (0.1 inch or more) in Westcliffe usually arrives around October 15, and the last of the season around May 2. Those are the middle dates across the winters of 1991–2020 at Westcliffe, CO, 0.4 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 40 days after the last snow.

Planting calendar for 81252

What to do and when, from the 50% frost dates for Westcliffe, Colorado
WhenWhat to do
April 2 – April 16Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
April 16 – April 30Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
May 14 – May 28Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
June 11 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by June 17Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by August 26Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
September 9 onwardPlant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter.

The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.

Where these figures come from

ZIP 81252 is under a mile from Westcliffe, CO, which stands at 7,873 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 81252 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Colorado →

Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.

Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.

ZIP codes measured at the same station

Other zone 5b places in Colorado