USDA Hardiness Zone 6a
Frost Dates for 81212 — Canon City, Colorado
NOAA 1991–2020 normals from Canon City, CO (5,378 ft), 3 miles east.
Updated
In Canon City, the last spring frost (32°F) is around May 4 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around October 7, as early as September 25 one year in ten, leaving a typical freeze-free season of 153 days (NOAA, Canon City, CO).
- Last spring frost
- May 4
- First fall frost
- October 7
- Growing season
- 153 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
- October 31
- Last snow
- April 27
- Winters with snow
- 100%
- Snow per year
- 38.3"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Canon City
Half of springs at Canon City, CO see their last 32°F night by May 4; only one in ten is past it by April 24, and one in ten still has one after May 18. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 13 20%, and after May 18 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 45% of the 110 Colorado stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 7 in half of years, as early as September 25 one year in ten, and holds off past October 19 one year in ten. A hard freeze of 28°F follows 10 days later, around October 17; in spring the one-in-ten date for 28°F is May 7, 11 days before the 32°F one. The freeze-free season lasts 153 days in a typical year, longer than at 66% of the 110 Colorado stations; it reaches 169 days one year in ten and falls short of 136 one year in ten. On average 144 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 16, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 14 and March 22.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 3 | May 7 | May 10 | May 13 | May 16 | May 19 | May 22 | May 26 | Jun 1 |
| 32°F | Apr 24 | Apr 28 | Apr 30 | May 2 | May 4 | May 6 | May 9 | May 13 | May 18 |
| 28°F | Apr 13 | Apr 17 | Apr 20 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 4 | May 7 |
| 24°F | Mar 31 | Apr 5 | Apr 9 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 30 |
| 20°F | Mar 15 | Mar 22 | Mar 27 | Mar 31 | Apr 2 | Apr 6 | Apr 10 | Apr 14 | Apr 19 |
| 16°F | Mar 1 | Mar 7 | Mar 12 | Mar 16 | Mar 22 | Mar 25 | Mar 31 | Apr 3 | Apr 10 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 14 | Sep 20 | Sep 23 | Sep 26 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 9 |
| 32°F | Sep 25 | Sep 29 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 12 | Oct 15 | Oct 19 |
| 28°F | Oct 3 | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 29 |
| 24°F | Oct 13 | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 20°F | Oct 19 | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 18 |
| 16°F | Oct 29 | Nov 2 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 19 | Nov 23 | Nov 28 |
Freeze probabilities 1991–2020 at Canon City, 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 81212 →Compare Canon City with another place →
Weather by month in Canon City
July is the warmest month at Canon City, CO, averaging 89°F by day and 59°F at night; December is the coldest at 49°F and 19°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 67% of years.
Warmth for growing adds up to 3,011 growing degree days a year (base 50°F), more than at 77% of the 110 Colorado stations. 32% of them (958) have built up by the end of June, and July adds the most, 742. Precipitation totals 14.1 inches a year, most in July (2.3") and least in December (0.5"); May to September bring 57% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 49 | 18 | 0.6 | 100% | 27 | 3 |
| Feb | 50 | 20 | 0.6 | 100% | 25 | 6 |
| Mar | 59 | 26 | 1.0 | 100% | 22 | 29 |
| Apr | 64 | 33 | 1.8 | 100% | 12 | 88 |
| May | 73 | 43 | 1.6 | 67% | 2 | 279 |
| Jun | 85 | 52 | 0.9 | 0% | 0 | 552 |
| Jul | 89 | 59 | 2.3 | 0% | 0 | 742 |
| Aug | 87 | 57 | 2.1 | 0% | 0 | 680 |
| Sep | 80 | 48 | 1.2 | 24% | <1 | 434 |
| Oct | 69 | 36 | 0.9 | 99% | 8 | 159 |
| Nov | 57 | 26 | 0.6 | 100% | 21 | 33 |
| Dec | 49 | 19 | 0.5 | 100% | 27 | 5 |
Monthly normals 1991–2020 at Canon City, CO (5,378 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, Westcliffe, CO, 25 miles southwest of Canon City and 2,495 feet higher, has a last frost 38 days later (June 11), a first frost 28 days earlier (September 9), a season 64 days shorter.
When it snows in Canon City, Colorado
The first measurable snow (0.1 inch or more) in Canon City usually arrives around October 31, and the last of the season around April 27. Those are the middle dates across the winters of 1991–2020 at Canon City, CO, 2.9 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 7 days after the last snow.
Planting calendar for 81212
| When | What to do |
|---|---|
| February 23 – March 9 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 9 – March 23 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 6 – April 20 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 4 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 15 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 7 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 81212 is 3 miles from Canon City, CO, which stands at 5,378 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 81212 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.