USDA Hardiness Zone 5b
Frost Dates for 80132 — Monument, Colorado
NOAA 1991–2020 normals from Monument, CO (7,080 ft), under a mile north.
Updated
In Monument, the last spring frost (32°F) is around May 14 in half of years and has passed by May 31 in nine years out of ten. The first fall frost comes around October 1, as early as September 16 one year in ten, leaving a typical freeze-free season of 138 days (NOAA, Monument, CO).
- Last spring frost
- May 14
- First fall frost
- October 1
- Growing season
- 138 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 10
- Last snow
- May 14
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
16 of 16 observed
NOAA normal
Frost risk by date in Monument
Half of springs at Monument, CO see their last 32°F night by May 14; only one in ten is past it by May 2, and one in ten still has one after May 31. Planting tender crops after May 20 leaves a 30% risk of a frost on them, after May 24 20%, and after May 31 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 October 1 in half of years, as early as September 16 one year in ten, and holds off past October 14 one year in ten. A hard freeze of 28°F follows 9 days later, around October 10; in spring the one-in-ten date for 28°F is May 16, 15 days before the 32°F one. The freeze-free season lasts 138 days in a typical year, shorter than at 54% of the 110 Colorado stations; it reaches 155 days one year in ten and falls short of 116 one year in ten. On average 184 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 13 days longer, to about May 27, and return around September 21. Severe cold of 16°F or below comes every winter, usually between November 6 and April 4.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 14 | May 18 | May 21 | May 24 | May 27 | May 31 | Jun 3 | Jun 6 | Jun 12 |
| 32°F | May 2 | May 6 | May 9 | May 11 | May 14 | May 17 | May 20 | May 24 | May 31 |
| 28°F | Apr 21 | Apr 26 | Apr 29 | May 1 | May 3 | May 5 | May 8 | May 11 | May 16 |
| 24°F | Apr 9 | Apr 15 | Apr 18 | Apr 21 | Apr 25 | Apr 28 | Apr 30 | May 3 | May 7 |
| 20°F | Mar 29 | Apr 4 | Apr 7 | Apr 11 | Apr 15 | Apr 18 | Apr 21 | Apr 25 | Apr 30 |
| 16°F | Mar 14 | Mar 21 | Mar 25 | Mar 31 | Apr 4 | Apr 8 | Apr 12 | Apr 16 | Apr 22 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 9 | Sep 13 | Sep 16 | Sep 19 | Sep 21 | Sep 23 | Sep 26 | Sep 30 | Oct 4 |
| 32°F | Sep 16 | Sep 21 | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 14 |
| 28°F | Sep 23 | Sep 30 | Oct 3 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 20 | Oct 25 |
| 24°F | Oct 2 | Oct 9 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 29 | Nov 2 |
| 20°F | Oct 14 | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 7 | Nov 12 |
| 16°F | Oct 21 | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 17 | Nov 22 |
Freeze probabilities 1991–2020 at Monument, 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 80132 →Compare Monument with another place →
Frost risk through the year in Monument
In Monument, the spring curve drops under 10% on May 31 and the fall curve passes 10% on September 16, 108 days later; that gap is shorter than at 57% of the 110 Colorado stations with frost dates. The spring risk falls from 90% to 10% over 29 days (May 2 to May 31) and the fall risk climbs from 10% to 90% over 28 days (September 16 to October 14): both ends of the season vary about as much. At Monument 3S, CO, 3 miles south, the same gap runs from May 30 to September 19, 4 days longer.
| Planted on | Another 32°F night | 28°F night |
|---|---|---|
| Apr 30 | over 90% | 65% |
| May 7 | 77% | 33% |
| May 1450% date | 50% | 14% |
| May 21 | 28% | under 10% |
| May 28 | 14% | under 10% |
| Jun 4 | under 10% | under 10% |
Weather by month in Monument
July is the warmest month at Monument, CO, averaging 83°F by day and 54°F at night; January is the coldest at 41°F and 16°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 1,953 growing degree days a year (base 50°F), fewer than at 65% of the 110 Colorado stations. 30% of them (583) have built up by the end of June, and July adds the most, 561. Precipitation totals 22.6 inches a year, most in April (3.2") and least in February (0.7"); May to September bring 56% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 41 | 16 | 0.9 | 100% | 30 | 0 |
| Feb | 43 | 18 | 0.7 | 100% | 26 | 0 |
| Mar | 50 | 23 | 1.6 | 100% | 28 | 4 |
| Apr | 57 | 29 | 3.2 | 100% | 20 | 30 |
| May | 68 | 39 | 2.4 | 93% | 6 | 156 |
| Jun | 79 | 47 | 3.0 | 9% | <1 | 393 |
| Jul | 83 | 54 | 2.7 | 0% | 0 | 561 |
| Aug | 80 | 52 | 3.0 | 0% | 0 | 484 |
| Sep | 72 | 44 | 1.6 | 49% | 3 | 258 |
| Oct | 60 | 33 | 1.3 | 100% | 16 | 61 |
| Nov | 48 | 22 | 1.1 | 100% | 26 | 7 |
| Dec | 41 | 17 | 1.1 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Monument, CO (7,080 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, Monument 3S, CO, 3 miles south of Monument and 259 feet lower, has a last frost 3 days later (May 17), the same first-frost date, a season 2 days shorter.
When it snows in Monument, Colorado
The first measurable snow (0.1 inch or more) in Monument usually arrives around October 10, and the last of the season around May 14. Those are the middle dates across the winters of 1991–2020 at Monument 2.9 N, CO, 1.1 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 on the day of the last snow.
Planting calendar for 80132
| When | What to do |
|---|---|
| March 5 – March 19 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 19 – April 2 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 16 – April 30 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 14 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 80132 is under a mile from Monument, CO, which stands at 7,080 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 80132 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.