USDA Hardiness Zone 6a
Frost Dates for 81001 — Pueblo, Colorado
NOAA 1991–2020 normals from WFO Pueblo, CO (4,653 ft), 3 miles east.
Updated
In Pueblo, the last spring frost (32°F) is around April 30 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 9, as early as September 28 one year in ten, leaving a typical freeze-free season of 162 days (NOAA, WFO Pueblo, CO).
- Last spring frost
- April 30
- First fall frost
- October 9
- Growing season
- 162 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- November 3
- Last snow
- April 14
- Winters with snow
- 100%
- Snow per year
- 28.3"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Pueblo
Half of springs at WFO Pueblo, CO see their last 32°F night by April 30; only one in ten is past it by April 16, and one in ten still has one after May 12. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 81% of the 110 Colorado stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 9 in half of years, as early as September 28 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 9 days later, around October 18; in spring the one-in-ten date for 28°F is May 4, 8 days before the 32°F one. The freeze-free season lasts 162 days in a typical year, longer than at 86% of the 110 Colorado stations; it reaches 180 days one year in ten and falls short of 146 one year in ten. On average 152 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 9 days longer, to about May 9, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 10 and March 16.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 28 | May 2 | May 4 | May 7 | May 9 | May 12 | May 14 | May 17 | May 23 |
| 32°F | Apr 16 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 4 | May 7 | May 12 |
| 28°F | Apr 3 | Apr 7 | Apr 11 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 28 | May 4 |
| 24°F | Mar 22 | Mar 28 | Mar 31 | Apr 3 | Apr 6 | Apr 8 | Apr 12 | Apr 17 | Apr 23 |
| 20°F | Mar 9 | Mar 15 | Mar 19 | Mar 24 | Mar 28 | Mar 31 | Apr 3 | Apr 7 | Apr 13 |
| 16°F | Feb 28 | Mar 4 | Mar 8 | Mar 11 | Mar 16 | Mar 20 | Mar 25 | Mar 30 | Apr 4 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 22 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 7 | Oct 9 | Oct 13 |
| 32°F | Sep 28 | Oct 1 | Oct 5 | Oct 7 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 22 |
| 28°F | Oct 5 | Oct 10 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 23 | Oct 26 | Oct 31 |
| 24°F | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Nov 1 | Nov 3 | Nov 8 |
| 20°F | Oct 19 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 5 | Nov 8 | Nov 12 | Nov 15 |
| 16°F | Oct 25 | Oct 31 | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 20 | Nov 24 |
Freeze probabilities 1991–2020 at WFO Pueblo, 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 81001 →Compare Pueblo with another place →
Frost risk through the year in Pueblo
In Pueblo, the spring curve drops under 10% on May 12 and the fall curve passes 10% on September 28, 139 days later; that gap is longer than at 86% of the 110 Colorado stations with frost dates. The spring risk falls from 90% to 10% over 26 days (April 16 to May 12) and the fall risk climbs from 10% to 90% over 24 days (September 28 to October 22): both ends of the season vary about as much. At Pueblo Rsvr, CO, 8 miles west, the same gap runs from May 8 to September 30, 6 days longer.
| Planted on | Another 32°F night | 28°F night |
|---|---|---|
| Apr 16 | over 90% | 57% |
| Apr 23 | 73% | 33% |
| Apr 3050% date | 50% | 17% |
| May 7 | 20% | under 10% |
| May 14 | under 10% | under 10% |
| May 21 | under 10% | under 10% |
Compared with the next station
The nearest other station, Pueblo Rsvr, CO, 8 miles west of Pueblo and 208 feet higher, has a last frost 4 days earlier (April 26), a first frost 4 days later (October 13), a season 4 days longer.
When it snows in Pueblo, Colorado
The first measurable snow (0.1 inch or more) in Pueblo usually arrives around November 3, and the last of the season around April 14. Those are the middle dates across the winters of 1991–2020 at Pueblo Mem Airport, CO, 3.9 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 16 days after the last snow.
Planting calendar for 81001
| When | What to do |
|---|---|
| February 19 – March 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 5 – March 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 2 – April 16 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 30 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 17 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 25 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 9 onward | Plant 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 81001 is 3 miles from WFO Pueblo, CO, which stands at 4,653 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 81001 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.
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.