Lakewood, Colorado Frost Dates, Growing Season & Hardiness Zone
Frost odds and planting zone for Lakewood for the 2027 season, based on 1991–2020 normals.
Last frost date
May 3
typical (50% chance of a later 32°F night)
Safer date: May 18 (10% risk)
earlyMay 3
typicalMay 18
safer
First fall frost
Oct 7
typical (50% chance it has happened by then)
Early-risk date: Sep 24 (10%)
Growing season
155 days
typical frost-free (32°F) season
Short year: 133 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)
Across the metro, the typical last frost runs from Apr 30 (Denver Water Dept.) to May 16 (Strontia Springs Dam), depending on where you live.
Half of years have their last 32°F night by May 3. In 1 year out of 10, a freeze still comes after May 18.
Based on NOAA station Lakewood (USC00054762), 3.5 mi N, elevation 5,640 ft (−17 ft vs. city center). Confidence: High.
When is the last frost in Lakewood?
The typical last 32°F night is May 3, and in 1 year out of 10 a freeze still comes after May 18. Cold 36°F nights (frost possible on plants) typically last longer, to around May 14. The last hard freeze (28°F) typically comes earlier, around Apr 22.
Lakewood has a long late-frost tail: 15 days separate the typical date (May 3) from the safer 1-in-10 date (May 18). If tender plants go out early, be ready to protect them on cold nights.
Cold nights don't end with the last freeze. The typical last 36°F night (frost possible on plants in low spots) comes around May 14, 11 days after the typical last 32°F night. On clear, calm nights, frost can form on leaves while the thermometer still reads above freezing.
| Threshold | 10% (safer) | 30% | 50% (typical) | 90% (early) |
|---|---|---|---|---|
| 36°F (frost possible on plants) | May 29 | May 20 | May 14 | May 1 |
| 32°F freeze | May 18 | May 8 | May 3 | Apr 19 |
| 28°F hard freeze | May 7 | Apr 29 | Apr 22 | Apr 5 |
All probabilities (10–90%)
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F (frost possible on plants) | May 29 | May 23 | May 20 | May 17 | May 14 | May 12 | May 9 | May 5 | May 1 |
| 32°F freeze | May 18 | May 12 | May 8 | May 6 | May 3 | May 1 | Apr 28 | Apr 24 | Apr 19 |
| 28°F hard freeze | May 7 | May 2 | Apr 29 | Apr 25 | Apr 22 | Apr 19 | Apr 15 | Apr 10 | Apr 5 |
Is it safe to plant after Mother's Day in Lakewood?
Many Lakewood-area gardeners wait for Mother's Day to plant (CSU PlantTalk). In 2027, it falls on May 9. As of that date, the chance of another 32°F night is between 20% and 30%, and the chance of another 36°F night (frost possible on plants) is about 70% (NOAA 1991–2020, Lakewood).
Is it too early to plant in Lakewood?
Before May 3 the odds of another 32°F night are better than even; after May 18 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 Lakewood?
The typical first fall freeze (32°F) comes by Oct 7, but 1 year in 10 it shows up as early as Sep 24. Cold 36°F nights (frost possible on plants) typically start around Sep 30, and the first hard freeze (28°F) typically comes around Oct 16.
To time a fall crop, count back from the typical first frost (Oct 7) or the safer Sep 24. The planting calendar works it out crop by crop.
| Threshold | 10% (early) | 30% | 50% (typical) | 90% (late) |
|---|---|---|---|---|
| 36°F (frost possible on plants) | Sep 16 | Sep 25 | Sep 30 | Oct 12 |
| 32°F freeze | Sep 24 | Oct 2 | Oct 7 | Oct 21 |
| 28°F hard freeze | Oct 1 | Oct 9 | Oct 16 | Oct 30 |
All probabilities (10–90%)
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F (frost possible on plants) | Sep 16 | Sep 21 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 12 |
| 32°F freeze | Sep 24 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 21 |
| 28°F hard freeze | Oct 1 | Oct 6 | Oct 9 | Oct 13 | Oct 16 | Oct 18 | Oct 21 | Oct 25 | Oct 30 |
How long is Lakewood's growing season?
Lakewood's frost-free season (32°F) typically runs 155 days. In about 1 year out of 10, it's shorter than 133 days.
That's enough time for most warm-season vegetables if they go in on time. Long-season crops do best started from transplants.
Growing degree days measure the heat available for crops to grow. The station averages 2,713 a year (base 50°F).
| Threshold | 10% (long year) | 50% (typical) | 90% (short year) |
|---|---|---|---|
| 36°F (frost possible on plants) | 156 days | 137 days | 117 days |
| 32°F freeze | 175 days | 155 days | 133 days |
| 28°F hard freeze | 198 days | 176 days | 154 days |
How does Lakewood's season compare?
Of the 20 Colorado cities with frost dates on this site, Lakewood has a typical frost-free season of 155 days, which is tied for the 11th longest.
Compared with the 56 U.S. cities with frost dates on this site, this typical frost-free season is longer than in 8 and shorter than in 46.
Growing degree days (base 50°F)
Annual normal: 2,713 GDD (NOAA flag R, 22 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 | 6 | 31 | 106 | 339 | 840 | 1,545 | 2,183 | 2,568 | 2,686 | 2,711 | 2,713 |
What growing zone is Lakewood? (USDA 2023)
On the 2023 USDA map, Lakewood is zone 6a (-10 to -5°F average coldest winter night). On the 2012 map, most of the city was 5b. Of the 7 city ZIPs listed in both tables, 5 moved up half a zone.
| ZIP | 2023 | 2012 | Change | Share of ZIP in Lakewood |
|---|---|---|---|---|
| 80214 mostly in city | 6a | 6a | unchanged | 75% |
| 80215 mostly in city | 6a | 6a | unchanged | 93% |
| 80226 mostly in city | 6a | 5b | +1 half zone (warmer) | 99% |
| 80227 mostly in city | 6a | 5b | +1 half zone (warmer) | 77% |
| 80228 mostly in city | 6a | 5b | +1 half zone (warmer) | 92% |
| 80232 mostly in city | 6a | 5b | +1 half zone (warmer) | 86% |
| 80235 | 6a | 5b | +1 half zone (warmer) | 23% |
Other ZIPs touching Lakewood
ZIPs outside the 802 prefix that overlap the city boundary:
- 80123: 2023 6a, 2012 5b (4.4% of the ZIP is in Lakewood)
- 80127: 2023 5b, 2012 5b (0.0% of the ZIP is in Lakewood)
- 80401: 2023 5b, 2012 5b (3.5% of the ZIP is in Lakewood)
- 80465: 2023 5b, 2012 5b (3.7% of the ZIP is in Lakewood)
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 Lakewood's frost dates?
No. Hardiness zones are based only on the average coldest winter temperature. They say nothing about when spring and fall frosts happen. Lakewood's frost dates come from NOAA's 1991–2020 frost probabilities, which did not change with the 2023 zone map. Use your zone to pick perennials that will survive winter, and your frost dates to time planting.
Why do Lakewood frost dates differ between websites?
Some sources list May 8 for Lakewood. That's the 30%-risk date: about 3 years in 10 still see a 32°F night after it. We headline the 50% (median) date, May 3.
May 18 is the 10%-risk, or 'safer', date. Only about 1 year in 10 has a 32°F night after it.
May 14 is the 50% date for a 36°F night (frost possible on plants), not a 32°F freeze. Sites that treat 36°F as the danger line show later dates.
Sites also pick different weather stations. Within 25 miles of the city center, the 14 stations that meet our quality rules put the typical (50%) last 32°F frost anywhere from Apr 30 to May 16 (table below).
| Date | What it is (NOAA 1991–2020) |
|---|---|
| May 8 | 32°F last frost, 30% risk (a 'balanced' date) |
| May 14 | 36°F last cold night, 50% (frost possible on plants) |
| May 18 | 32°F last frost, 10% risk (the 'safer' date) |
| Apr 22 | 28°F last hard freeze, 50% |
| May 5 | 32°F last frost, 50%, at Wheat Ridge 2 (nearest station with NOAA flag S) |
| Station | Distance | Elevation | Typical last frost |
|---|---|---|---|
| Denver Water Dept. | 6.2 mi ENE | 5,228 ft | Apr 30 |
| Marston Filter Plant | 6.0 mi SSE | 5,610 ft | May 2 |
| Northglenn | 14.9 mi NNE | 5,407 ft | May 2 |
| Lakewood used here | 3.5 mi N | 5,640 ft | May 3 |
| Ralston Reservoir | 11.0 mi NW | 5,900 ft | May 3 |
| Denver-Stapleton | 13.9 mi ENE | 5,286 ft | May 4 |
| Wheat Ridge 2 | 5.3 mi N | 5,398 ft | May 5 |
| Denver Centennial Airport | 16.8 mi ESE | 5,883 ft | May 5 |
| Boulder | 21.7 mi NNW | 5,484 ft | May 6 |
| Cherry Creek Dam | 16.0 mi ESE | 5,647 ft | May 7 |
| Kassler | 14.5 mi S | 5,587 ft | May 8 |
| Parker | 23.3 mi ESE | 5,904 ft | May 9 |
| Strontia Springs Dam | 18.3 mi S | 5,840 ft | May 16 |
| Roxborough State Park | 18.9 mi S | 6,117 ft | May 16 |
Which weather station is this based on?
- Station
- Lakewood (NOAA USC00054762, COOP)
- Distance
- 3.5 mi N of the city center
- Elevation
- 5,640 ft; city center 5,657 ft (USGS), difference −17 ft
- Record
- NOAA completeness flag R, 24 of 30 years (1991–2020)
- Confidence
- High (rule)
Confidence: High. The station is close (3.5 miles from the city center), its elevation differs by just 17 ft, and its frost statistics meet our completeness rule (NOAA flag R, 24 of 30 years).
Caveat: NOAA flags this station's frost statistics 'R' (representative). They rest on 24 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 Wheat Ridge 2, 5.3 mi away; its typical last frost is May 5.
| Station | ID | Distance | Elev. (Δ) | Last frost 50% | First frost 50% | Season 50% | NOAA flag / years |
|---|---|---|---|---|---|---|---|
| Lakewood | USC00054762 | 3.5 mi N | 5,640 ft (-17) | May 3 | Oct 7 | 155 d | R / 24 |
| Wheat Ridge 2 | USC00058995 | 5.3 mi N | 5,398 ft (-259) | May 5 | Oct 5 | 151 d | S / 28 |
| Marston Filter Plant | USC00055402 | 6.0 mi SSE | 5,610 ft (-47) | May 2 | Oct 11 | 160 d | R / 18 |
| Denver Water Dept. | USC00052223 | 6.2 mi ENE | 5,228 ft (-429) | Apr 30 | Oct 12 | 165 d | R / 22 |
| Ralston Reservoir | USC00056816 | 11.0 mi NW | 5,900 ft (+243) | May 3 | Oct 14 | 161 d | R / 22 |
| Denver-Stapleton | USW00023062 | 13.9 mi ENE | 5,286 ft (-371) | May 4 | Oct 8 | 156 d | S / 28 |
| Kassler | USC00054452 | 14.5 mi S | 5,587 ft (-70) | May 8 | Oct 3 | 147 d | R / 23 |
| Northglenn | USC00055984 | 14.9 mi NNE | 5,407 ft (-250) | May 2 | Oct 11 | 160 d | S / 26 |
| Cherry Creek Dam | USC00051547 | 16.0 mi ESE | 5,647 ft (-10) | May 7 | Oct 8 | 152 d | R / 13 |
| Denver Centennial Airport | USW00093067 | 16.8 mi ESE | 5,883 ft (+226) | May 5 | Oct 8 | 154 d | R / 20 |
| Strontia Springs Dam | USC00058022 | 18.3 mi S | 5,840 ft (+183) | May 16 | Sep 29 | 132 d | R / 19 |
| Roxborough State Park | USC00057249 | 18.9 mi S | 6,117 ft (+460) | May 16 | Oct 1 | 136 d | R / 24 |
| Boulder | USC00050848 | 21.7 mi NNW | 5,484 ft (-173) | May 6 | Oct 5 | 151 d | S / 26 |
| Parker | USC00056323 | 23.3 mi ESE | 5,904 ft (+247) | May 9 | Oct 3 | 145 d | R / 16 |
Other stations within 25 mi (not used)
- Evergreen (USC00052790), 11.3 mi WSW, 6,985 ft: typical last frost May 23. Not used: |elev diff| 1328 ft > 500 ft.
- Coal Creek Canyon (USC00051681), 19.6 mi NW, 8,950 ft: typical last frost Jun 5. Not used: |elev diff| 3293 ft > 500 ft.
- Gross Reservoir (USC00053629), 20.5 mi NW, 7,970 ft: typical last frost May 24. Not used: |elev diff| 2313 ft > 500 ft.
- Brighton 3 SE (USC00050950), 22.6 mi NE, 5,016 ft: typical last frost May 3. Not used: |elev diff| 641 ft > 500 ft.
- Castle Rock (USC00051401), 22.9 mi SSE, 6,185 ft: typical last frost May 9. Not used: |elev diff| 528 ft > 500 ft.
92 other NOAA normals stations within 40 km (mostly rain gauges) have no frost statistics.
Lakewood planting dates at a glance
Balanced dates use the 30%-risk last-frost date as the anchor. The Lakewood 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 23 – May 7 | Jun 11 | – |
| Peppers | Mar 27 – Apr 10 | May 22 | – |
| Potatoes | – | Apr 24 – May 8 | – |
| Onions (dry, from sets) | – | Apr 10–24 | – |
| Peas | – | Apr 10–24 | sow by Jul 20 |
| Lettuce (leaf) | – | Apr 10–24 | sow by Jul 25 |
| Carrots | – | Apr 24 – May 8 | sow by Jul 15 |
| Beans (snap) | – | May 8 | sow by Jul 11 |
| Summer squash | – | May 8 | sow by Jul 21 |
| Broccoli | Feb 20 – Mar 6 | Apr 10–24 | transplant by Jul 20 |
| Cabbage | Feb 20 – Mar 6 | Apr 10–24 | transplant by Jun 30 |
| Cauliflower | Mar 6–20 | Apr 24 – May 8 | – |
| Kohlrabi | – | Apr 10–24 | sow by Aug 4 |
| Green onions | – | Apr 10–24 | sow by Jul 25 |
| Radishes | – | Apr 10–24 | sow by Aug 24 |
| Spinach | – | Apr 10–24 | sow by Aug 14 |
| Turnips | – | Apr 10–24 | sow by Aug 4 |
| Beets | – | Apr 24 – May 8 | sow by Jul 25 |
| Swiss chard | – | Apr 24 – May 8 | sow by Jul 25 |
| Parsnips | – | Apr 24 – May 8 | – |
| Sweet corn | – | May 8 | – |
| Cucumbers | – | May 8 | sow by Jul 16 |
| Eggplant | Mar 20 – Apr 10 | May 22 | – |
| Cantaloupe | – | May 22 | – |
| Watermelon | – | May 22 | – |
| Winter squash | – | May 22 | – |
| Garlic | – | – | plant Oct 1–14 |
When to plant tomatoes in Lakewood · Fall planting dates for Lakewood
Frost dates near Lakewood
| City | Distance | Last frost | First frost | Season | Zone 2023 |
|---|---|---|---|---|---|
| Denver frost dates | 7 mi | Apr 30 | Oct 12 | 165 days | 6a |
| Littleton frost dates | 9 mi | May 2 | Oct 11 | 160 days | 5b–6a |
| Arvada frost dates | 9 mi | May 5 | Oct 5 | 151 days | 6a |
| Centennial frost dates | 15 mi | May 5 | Oct 8 | 154 days | 6a |
| Thornton frost dates | 18 mi | May 2 | Oct 11 | 160 days | 6a |
| Aurora frost dates | 21 mi | May 7 | Oct 8 | 152 days | 6a |
Frequently asked questions
What is the average last frost date in Lakewood?
May 3 is the median (50%) date for Lakewood's last 32°F night, from NOAA 1991–2020 normals at Lakewood. To play it safe, use May 18: only about 1 year in 10 has a freeze after it.
When is the first frost in Lakewood?
Typically by Oct 7 for the first 32°F night, though about 1 year in 10 it comes as early as Sep 24. The first 36°F night (frost possible on plants) typically shows up around Sep 30.
What growing zone is Lakewood, Colorado? Is Lakewood zone 5 or 6?
Zone 6a (zone 6 for short) is Lakewood'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 Lakewood?
Before May 3, 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 May 3 and May 18. 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 quite. A freeze is when the air reaches 32°F. Frost is ice that forms on surfaces, and on calm, clear nights it can form with the air a few degrees above freezing. So in Lakewood, the first 36°F night (frost possible on plants) typically comes around Sep 30, before the first 32°F night (Oct 7).
Download & sources
- Add Lakewood 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 USC00054762); 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.