Pueblo, Colorado Frost Dates, Growing Season & Hardiness Zone
Frost odds and planting zone for Pueblo for the 2027 season, based on 1991–2020 normals.
Last frost date
Apr 26
typical (50% chance of a later 32°F night)
Safer date: May 8 (10% risk)
earlyApr 26
typicalMay 8
safer
First fall frost
Oct 13
typical (50% chance it has happened by then)
Early-risk date: Sep 30 (10%)
Growing season
166 days
typical frost-free (32°F) season
Short year: 149 days (1 year in 10 is shorter)
USDA hardiness zone
6a
2023 map: -10 to -5°F average coldest night
2012 map: 5b (most of the city)
Stations around the metro don't all agree. The typical last frost is as early as Apr 26 at Pueblo Reservoir and as late as Apr 30 at Pueblo Memorial Airport.
Half of years have their last 32°F night by Apr 26. In 1 year out of 10, a freeze still comes after May 8.
Based on NOAA station Pueblo Reservoir (USC00056765), 5.8 mi W, elevation 4,861 ft (+197 ft vs. city center). Confidence: High.
When is the last frost in Pueblo?
The typical last 32°F night is Apr 26, and in 1 year out of 10 a freeze still comes after May 8. Cold 36°F nights (frost possible on plants) typically last longer, to around May 6. The last hard freeze (28°F) typically comes earlier, around Apr 16.
Planting between the typical date (Apr 26) and the safer 1-in-10 date (May 8) is a bet. Over those 12 days, let the 10-day forecast guide you.
Cool nights hang on after the last freeze: the typical last 36°F night (frost possible on plants in low spots) is around May 6, 10 days later than the typical last 32°F night. Frost can form on leaves on clear, calm nights even with the thermometer above freezing.
| Threshold | 10% (safer) | 30% | 50% (typical) | 90% (early) |
|---|---|---|---|---|
| 36°F (frost possible on plants) | May 19 | May 11 | May 6 | Apr 24 |
| 32°F freeze | May 8 | May 1 | Apr 26 | Apr 13 |
| 28°F hard freeze | Apr 30 | Apr 22 | Apr 16 | Apr 1 |
All probabilities (10–90%)
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F (frost possible on plants) | May 19 | May 14 | May 11 | May 8 | May 6 | May 3 | May 1 | Apr 28 | Apr 24 |
| 32°F freeze | May 8 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 24 | Apr 20 | Apr 17 | Apr 13 |
| 28°F hard freeze | Apr 30 | Apr 25 | Apr 22 | Apr 18 | Apr 16 | Apr 13 | Apr 9 | Apr 6 | Apr 1 |
Is it safe to plant after Mother's Day in Pueblo?
Around Pueblo, many gardeners use Mother's Day as their cue to plant (CSU PlantTalk). It falls on May 9 in 2027. From then on, the chance of another 32°F night is less than 10%; for a 36°F night (frost possible on plants) it's between 30% and 40% (NOAA 1991–2020, Pueblo Reservoir).
Is it too early to plant in Pueblo?
Before Apr 26 the odds of another 32°F night are better than even; after May 8 they are about 1 in 10 or less.
Today's risk is computed in your browser from the same NOAA probability table, shown as the range between the two nearest NOAA probability levels.
When is the first frost in Pueblo?
Half of years get their first 32°F night by Oct 13. In 1 year out of 10, it arrives as early as Sep 30. The first 36°F night (frost possible on plants) typically comes around Oct 5, and the first 28°F hard freeze around Oct 22.
To time a fall crop, count back from the typical first frost (Oct 13) or the safer Sep 30. The planting calendar works it out crop by crop.
| Threshold | 10% (early) | 30% | 50% (typical) | 90% (late) |
|---|---|---|---|---|
| 36°F (frost possible on plants) | Sep 24 | Sep 30 | Oct 5 | Oct 17 |
| 32°F freeze | Sep 30 | Oct 7 | Oct 13 | Oct 25 |
| 28°F hard freeze | Oct 6 | Oct 16 | Oct 22 | Nov 4 |
All probabilities (10–90%)
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F (frost possible on plants) | Sep 24 | Sep 28 | Sep 30 | Oct 3 | Oct 5 | Oct 7 | Oct 10 | Oct 12 | Oct 17 |
| 32°F freeze | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 15 | Oct 18 | Oct 21 | Oct 25 |
| 28°F hard freeze | Oct 6 | Oct 12 | Oct 16 | Oct 20 | Oct 22 | Oct 25 | Oct 27 | Oct 31 | Nov 4 |
How long is Pueblo's growing season?
In a typical year, Pueblo gets 166 days between the last and first 32°F nights. About 1 year in 10, the season is shorter than 149 days.
A season this long fits most warm-season vegetables planted on time. Long-season crops do best when started from transplants.
Each year the station logs an average of 3,507 growing degree days (base 50°F), a measure of the heat available for crop growth.
| Threshold | 10% (long year) | 50% (typical) | 90% (short year) |
|---|---|---|---|
| 36°F (frost possible on plants) | 166 days | 150 days | 133 days |
| 32°F freeze | 184 days | 166 days | 149 days |
| 28°F hard freeze | 208 days | 186 days | 165 days |
How does Pueblo's season compare?
Of the 20 Colorado cities with frost dates on this site, Pueblo has a typical frost-free season of 166 days, which is the 2nd longest.
Among the 56 U.S. cities with frost dates on this site, the typical frost-free season here is longer than in 18 of them and shorter than in 37.
Growing degree days (base 50°F)
Annual normal: 3,507 GDD (NOAA flag R, 23 years). Running total by the end of each month (sum of NOAA daily GDD normals, so the year-end total can differ slightly from the annual normal):
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 8 | 47 | 169 | 524 | 1,178 | 2,019 | 2,788 | 3,292 | 3,471 | 3,504 | 3,509 |
What growing zone is Pueblo? (USDA 2023)
The 2023 USDA map puts Pueblo in zone 6a (-10 to -5°F average coldest winter night). On the 2012 map, most of the city was 5b. Comparing ZIPs listed in both tables, 6 of 7 moved up half a zone.
| ZIP | 2023 | 2012 | Change | Share of ZIP in Pueblo |
|---|---|---|---|---|
| 81001 mostly in city | 6a | 5b | +1 half zone (warmer) | 54% |
| 81003 mostly in city | 6a | 5b | +1 half zone (warmer) | 57% |
| 81004 | 6a | 5b | +1 half zone (warmer) | 5% |
| 81005 | 6a | 5b | +1 half zone (warmer) | 5% |
| 81006 | 6a | 5b | +1 half zone (warmer) | 2% |
| 81007 | 6a | 6a | unchanged | 0% |
| 81008 | 6a | 5b | +1 half zone (warmer) | 10% |
Other ZIPs touching Pueblo and PO-box ZIPs
ZIPs outside the 810 prefix that overlap the city boundary:
- none
PO-box and single-address 810xx ZIPs have no Census area, so we cannot tell which city they serve: 81002 (6a/5b), 81009 (5b/5b), 81010 (6a/5b), 81011 (6a/5b), 81012 (6a/5b), 81019 (6a/6a), 81020 (6a/6a), 81021 (5b/5b), 81022 (6a/5b), 81023 (6a/5b), 81024 (6a/6a), 81025 (6a/5b), 81027 (6a/6a), 81029 (6b/6a), 81030 (6a/5b), 81033 (n/a/5b), 81034 (5b/5b), 81036 (6a/6a), 81038 (6a/6a), 81039 (6a/5b), 81040 (6a/5b), 81041 (6a/6a), 81043 (6a/6a), 81044 (6a/6a), 81045 (5b/5b), 81046 (6a/6a), 81047 (6a/6a), 81049 (6a/6a), 81050 (6a/5b), 81052 (6a/6a), 81054 (6a/6a), 81055 (6a/5b), 81057 (6a/6a), 81058 (6a/5b), 81059 (6a/6a), 81062 (6a/5b), 81063 (5b/5b), 81064 (6b/6a), 81067 (6a/5b), 81069 (6a/5b), 81071 (6a/5b), 81073 (6b/6a), 81076 (5b/5b), 81077 (6a/5b), 81081 (6a/6a), 81082 (6a/6a), 81084 (6b/6a), 81087 (6b/6a), 81089 (6a/6a), 81090 (6b/6a), 81091 (6a/6a), 81092 (6a/6a) (2023/2012).
Zones: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed 2026-10-08. Shown as published in the ZIP tables; this page does not show a zone map. Not the official USDA Plant Hardiness Zone Map (official map: planthardiness.ars.usda.gov).
Does the new zone change Pueblo's frost dates?
No. A hardiness zone reflects only the average coldest winter temperature, not the timing of spring or fall frost. Pueblo's frost dates come from NOAA's 1991–2020 frost probabilities, and the 2023 zone map didn't change them. Pick perennials that survive winter by zone; time your planting by frost dates.
Why do Pueblo frost dates differ between websites?
You may see May 1 given as Pueblo's last frost date. That's the 30%-risk date, meaning about 3 years in 10 still have a 32°F night after it. Our headline date is Apr 26, the 50% (median) date.
May 8 is the date we call 'safer': it's the 10%-risk date, with a 32°F night after it in only about 1 year in 10.
May 6 is the typical (50%) date for a 36°F night (frost possible on plants), not a 32°F freeze. Any site that draws the line at 36°F will show later dates.
The choice of weather station matters too. The 2 stations within 25 miles of the city center that pass our quality rules give typical (50%) last 32°F frost dates from Apr 26 to Apr 30; see the table below.
| Date | What it is (NOAA 1991–2020) |
|---|---|
| May 1 | 32°F last frost, 30% risk (a 'balanced' date) |
| May 6 | 36°F last cold night, 50% (frost possible on plants) |
| May 8 | 32°F last frost, 10% risk (the 'safer' date) |
| Apr 16 | 28°F last hard freeze, 50% |
| Apr 30 | 32°F last frost, 50%, at Pueblo Memorial Airport (nearest station with NOAA flag S) |
| Station | Distance | Elevation | Typical last frost |
|---|---|---|---|
| Pueblo Reservoir used here | 5.8 mi W | 4,861 ft | Apr 26 |
| Pueblo Memorial Airport | 6.3 mi ENE | 4,720 ft | Apr 30 |
Which weather station is this based on?
- Station
- Pueblo Reservoir (NOAA USC00056765, COOP)
- Distance
- 5.8 mi W of the city center
- Elevation
- 4,861 ft; city center 4,664 ft (USGS), difference +197 ft
- Record
- NOAA completeness flag R, 25 of 30 years (1991–2020)
- Confidence
- High (rule)
Confidence: High. At 5.8 miles from the city center and only 197 ft off in elevation, with frost statistics that meet our completeness rule (NOAA flag R, 25 of 30 years), this station is a close match.
Caveat: NOAA flags this station's frost statistics 'R' (representative). They rest on 25 of the 30 years in 1991–2020, with missing months filled in from surrounding stations. The nearest station with a full 'S' (standard) record is Pueblo Memorial Airport, 6.3 mi away; its typical last frost is Apr 30.
| Station | ID | Distance | Elev. (Δ) | Last frost 50% | First frost 50% | Season 50% | NOAA flag / years |
|---|---|---|---|---|---|---|---|
| Pueblo Reservoir | USC00056765 | 5.8 mi W | 4,861 ft (+197) | Apr 26 | Oct 13 | 166 d | R / 25 |
| Pueblo Memorial Airport | USW00093058 | 6.3 mi ENE | 4,720 ft (+56) | Apr 30 | Oct 9 | 161 d | S / 29 |
Other stations within 25 mi (not used)
- Pueblo Weather Office (USC00058992), 4.9 mi E, 4,653 ft: typical last frost Apr 30. Not used: frost normals incomplete or flagged (needs all 81 values with S/R flags, or values missing only because NOAA's probability of occurrence is below 10%).
14 other NOAA normals stations within 40 km (mostly rain gauges) have no frost statistics.
Pueblo planting dates at a glance
Balanced dates use the 30%-risk last-frost date as the anchor. The Pueblo planting calendar has typical and safe dates, fall planting and a month-by-month list for 27 vegetables.
| Crop | Start indoors | Plant outdoors (balanced) | Fall |
|---|---|---|---|
| Tomatoes | Apr 14–28 | Jun 2 | – |
| Peppers | Mar 20 – Apr 3 | May 15 | – |
| Potatoes | – | Apr 17 – May 1 | – |
| Onions (dry, from sets) | – | Apr 3–17 | – |
| Peas | – | Apr 3–17 | sow by Jul 26 |
| Lettuce (leaf) | – | Apr 3–17 | sow by Jul 31 |
| Carrots | – | Apr 17 – May 1 | sow by Jul 21 |
| Beans (snap) | – | May 1 | sow by Jul 17 |
| Summer squash | – | May 1 | sow by Jul 27 |
| Broccoli | Feb 13–27 | Apr 3–17 | transplant by Jul 26 |
| Cabbage | Feb 13–27 | Apr 3–17 | transplant by Jul 6 |
| Cauliflower | Feb 27 – Mar 13 | Apr 17 – May 1 | – |
| Kohlrabi | – | Apr 3–17 | sow by Aug 10 |
| Green onions | – | Apr 3–17 | sow by Jul 31 |
| Radishes | – | Apr 3–17 | sow by Aug 30 |
| Spinach | – | Apr 3–17 | sow by Aug 20 |
| Turnips | – | Apr 3–17 | sow by Aug 10 |
| Beets | – | Apr 17 – May 1 | sow by Jul 31 |
| Swiss chard | – | Apr 17 – May 1 | sow by Jul 31 |
| Parsnips | – | Apr 17 – May 1 | – |
| Sweet corn | – | May 1 | – |
| Cucumbers | – | May 1 | sow by Jul 22 |
| Eggplant | Mar 13 – Apr 3 | May 15 | – |
| Cantaloupe | – | May 15 | – |
| Watermelon | – | May 15 | – |
| Winter squash | – | May 15 | – |
| Garlic | – | – | plant Oct 1–14 |
When to plant tomatoes in Pueblo · Fall planting dates for Pueblo
Frost dates near Pueblo
| City | Distance | Last frost | First frost | Season | Zone 2023 |
|---|---|---|---|---|---|
| Colorado Springs frost dates | 42 mi | May 3 | Oct 8 | 158 days | 5b–6a |
| Castle Rock frost dates | 78 mi | May 9 | Oct 2 | 143 days | 5b |
| Parker frost dates | 86 mi | May 9 | Oct 3 | 145 days | 5b–6a |
| Centennial frost dates | 92 mi | May 5 | Oct 8 | 154 days | 6a |
| Littleton frost dates | 94 mi | May 2 | Oct 11 | 160 days | 5b–6a |
| Aurora frost dates | 100 mi | May 7 | Oct 8 | 152 days | 6a |
Frequently asked questions
What is the average last frost date in Pueblo?
The typical (median, 50%) last 32°F night in Pueblo is Apr 26, based on NOAA 1991–2020 normals at Pueblo Reservoir. For a safer target, use May 8; after that, only about 1 year in 10 still has a freeze.
When is the first frost in Pueblo?
Expect the first 32°F night by Oct 13 in a typical year, and as early as Sep 30 in about 1 year out of 10. Cold 36°F nights (frost possible on plants) typically start around Oct 5.
What growing zone is Pueblo, Colorado? Is Pueblo zone 5 or 6?
Zone 6a (zone 6 for short) is Pueblo's USDA hardiness zone on the 2023 map. Most of the city was 5b on the older 2012 map, so you'll still find 'zone 5' in older references.
Is it too early to plant in Pueblo?
Before Apr 26, yes, for anything frost-tender. Until then, the odds of another 32°F night are better than even. The risk falls from 50% to 10% between Apr 26 and May 8. Peas, lettuce and other cool-season crops can go in weeks earlier; the planting calendar has dates.
What temperature is a killing frost?
It depends on the crop. Tender plants such as tomatoes are killed by a light frost, which CSU Extension describes as 28–32°F; below 28°F is a heavy frost. We show NOAA odds for 36°F (frost possible on plants), 32°F (freeze, our headline) and 28°F (hard freeze).
Is first frost the same as first freeze?
Not exactly. A freeze is about the air reaching 32°F. Frost is ice on surfaces, which can form on calm, clear nights while the air is still a few degrees above freezing. So in Pueblo, the first 36°F night (frost possible on plants) typically comes around Oct 5, ahead of the first 32°F night (Oct 13).
Download & sources
- Add Pueblo frost & planting dates to your calendar (.ics, 2027)
- Printable planting calendar (PDF)
- How these numbers are calculated
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal and daily normals, station USC00056765); USDA Plant Hardiness Zone ZIP tables 2023 and 2012 by the PRISM Group, Oregon State University; Census 2020 ZIP/place relationship file; USGS elevation. Long-term odds, not a forecast. Figures and sentences are generated from these data by fixed rules; see the methodology. Last updated 2026-10-08.