USDA Hardiness Zone 5b
Frost Dates for 80921 — Colorado Springs, Colorado
NOAA 1991–2020 normals from Monument 3S, CO (6,821 ft), 2 miles northwest.
Updated
In Colorado Springs, the last spring frost (32°F) is around May 17 in half of years and has passed by May 30 in nine years out of ten. The first fall frost comes around October 1, as early as September 19 one year in ten, leaving a typical freeze-free season of 136 days (NOAA, Monument 3S, CO).
- Last spring frost
- May 17
- First fall frost
- October 1
- Growing season
- 136 days
- Hardiness zone
- 5b
50% probability
50% probability
freeze-free, 50%
-15 to -10°F (-26.1 to -23.3°C) coldest night
- First snow
- October 25
- Last snow
- May 3
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
17 of 17 observed
NOAA normal
Frost risk by date in Colorado Springs
Half of springs at Monument 3S, CO see their last 32°F night by May 17; only one in ten is past it by May 5, and one in ten still has one after May 30. Planting tender crops after May 22 leaves a 30% risk of a frost on them, after May 25 20%, and after May 30 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 67% of the 110 Colorado stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 1 in half of years, as early as September 19 one year in ten, and holds off past October 12 one year in ten. A hard freeze of 28°F follows 8 days later, around October 9; in spring the one-in-ten date for 28°F is May 20, 10 days before the 32°F one. The freeze-free season lasts 136 days in a typical year, shorter than at 55% of the 110 Colorado stations; it reaches 153 days one year in ten and falls short of 117 one year in ten. On average 183 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 12 days longer, to about May 29, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 3 and April 3.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 16 | May 20 | May 23 | May 26 | May 29 | May 31 | Jun 3 | Jun 7 | Jun 12 |
| 32°F | May 5 | May 8 | May 12 | May 14 | May 17 | May 19 | May 22 | May 25 | May 30 |
| 28°F | Apr 26 | Apr 30 | May 2 | May 4 | May 6 | May 9 | May 11 | May 15 | May 20 |
| 24°F | Apr 14 | Apr 19 | Apr 22 | Apr 26 | Apr 29 | Apr 30 | May 3 | May 6 | May 10 |
| 20°F | Mar 31 | Apr 4 | Apr 8 | Apr 13 | Apr 17 | Apr 19 | Apr 23 | Apr 27 | May 1 |
| 16°F | Mar 15 | Mar 22 | Mar 27 | Mar 31 | Apr 3 | Apr 6 | Apr 11 | Apr 16 | Apr 22 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 9 | Sep 14 | Sep 17 | Sep 21 | Sep 23 | Sep 25 | Sep 27 | Sep 30 | Oct 2 |
| 32°F | Sep 19 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 12 |
| 28°F | Sep 28 | Oct 2 | Oct 4 | Oct 7 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 20 |
| 24°F | Oct 5 | Oct 9 | Oct 12 | Oct 15 | Oct 17 | Oct 19 | Oct 21 | Oct 24 | Oct 29 |
| 20°F | Oct 12 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 19 | Oct 23 | Oct 28 | Oct 31 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 18 |
Freeze probabilities 1991–2020 at Monument 3S, 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 80921 →Compare Colorado Springs with another place →
Weather by month in Colorado Springs
July is the warmest month at Monument 3S, CO, averaging 84°F by day and 53°F at night; February is the coldest at 43°F and 14°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month.
Warmth for growing adds up to 2,075 growing degree days a year (base 50°F), fewer than at 60% of the 110 Colorado stations. 29% of them (591) have built up by the end of June, and July adds the most, 570.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 43 | 14 | 100% | 31 | 0 |
| Feb | 43 | 14 | 100% | 26 | 2 |
| Mar | 52 | 23 | 100% | 27 | 10 |
| Apr | 57 | 29 | 100% | 20 | 34 |
| May | 67 | 38 | 97% | 8 | 157 |
| Jun | 79 | 47 | 6% | 0 | 388 |
| Jul | 84 | 53 | 0% | 0 | 570 |
| Aug | 81 | 51 | 0% | 0 | 502 |
| Sep | 75 | 44 | 45% | 1 | 305 |
| Oct | 63 | 32 | 100% | 16 | 91 |
| Nov | 52 | 22 | 100% | 24 | 14 |
| Dec | 43 | 15 | 100% | 30 | 1 |
Monthly normals 1991–2020 at Monument 3S, CO (6,821 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, Black Forest 6WNW, CO, 2 miles southeast of Colorado Springs, has a last frost 6 days earlier (May 11), a first frost 5 days later (October 6), a season 11 days longer.
When it snows in Colorado Springs, Colorado
The first measurable snow (0.1 inch or more) in Colorado Springs usually arrives around October 25, and the last of the season around May 3. Those are the middle dates across the winters of 1991–2020 at Gleneagle 0.4 WNW, 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 14 days after the last snow.
Planting calendar for 80921
| When | What to do |
|---|---|
| March 8 – March 22 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 22 – April 5 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 19 – May 3 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 17 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 9 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 17 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 1 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 80921 is 2 miles from Monument 3S, CO, which stands at 6,821 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 80921 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.
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.