USDA Hardiness Zone 5a
Frost Dates for 80459 — Kremmling, Colorado
NOAA 1991–2020 normals from Kremmling, CO (7,460 ft), 7 miles southeast.
Updated
In Kremmling, the last spring frost (32°F) is around June 14 in half of years and has passed by June 30 in nine years out of ten. The first fall frost comes around September 5, as early as August 26 one year in ten, leaving a typical freeze-free season of 80 days (NOAA, Kremmling, CO).
- Last spring frost
- June 14
- First fall frost
- September 5
- Growing season
- 80 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- October 20
- Last snow
- May 3
- Winters with snow
- 100%
- Snow per year
- 52.4"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Kremmling
Half of springs at Kremmling, CO see their last 32°F night by June 14; only one in ten is past it by June 1, and one in ten still has one after June 30. Planting tender crops after June 21 leaves a 30% risk of a frost on them, after June 24 20%, and after June 30 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 75% of the 110 Colorado stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 5 in half of years, as early as August 26 one year in ten, and holds off past September 16 one year in ten. A hard freeze of 28°F follows 11 days later, around September 16; in spring the one-in-ten date for 28°F is June 11, 19 days before the 32°F one. The freeze-free season lasts 80 days in a typical year, shorter than at 96% of the 110 Colorado stations; it reaches 99 days one year in ten and falls short of 60 one year in ten. On average 235 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between October 18 and April 16.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | Jun 1 | Jun 5 | Jun 8 | Jun 11 | Jun 14 | Jun 17 | Jun 21 | Jun 24 | Jun 30 |
| 28°F | May 13 | May 18 | May 21 | May 24 | May 28 | May 31 | Jun 2 | Jun 6 | Jun 11 |
| 24°F | Apr 30 | May 3 | May 6 | May 8 | May 11 | May 15 | May 18 | May 22 | May 28 |
| 20°F | Apr 16 | Apr 21 | Apr 25 | Apr 29 | May 1 | May 3 | May 6 | May 9 | May 15 |
| 16°F | Apr 2 | Apr 6 | Apr 9 | Apr 13 | Apr 16 | Apr 20 | Apr 24 | Apr 29 | May 4 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | Aug 26 | Aug 30 | Sep 1 | Sep 3 | Sep 5 | Sep 8 | Sep 10 | Sep 13 | Sep 16 |
| 28°F | Sep 4 | Sep 9 | Sep 11 | Sep 14 | Sep 16 | Sep 18 | Sep 20 | Sep 23 | Sep 27 |
| 24°F | Sep 15 | Sep 18 | Sep 22 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 8 |
| 20°F | Sep 23 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 21 |
| 16°F | Oct 2 | Oct 7 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 27 | Nov 1 |
Freeze probabilities 1991–2020 at Kremmling, 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 80459 →Compare Kremmling with another place →
Weather by month in Kremmling
July is the warmest month at Kremmling, CO, averaging 81°F by day and 44°F at night; January is the coldest at 26°F and -1°F. A freezing night is all but certain in every month from September to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 90% of years.
Warmth for growing adds up to 1,130 growing degree days a year (base 50°F), fewer than at 87% of the 110 Colorado stations. 24% of them (271) have built up by the end of June, and July adds the most, 396. Precipitation totals 11.9 inches a year, most in May (1.4") and least in January (0.7"); May to September bring 53% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 26 | -1 | 0.7 | 100% | 31 | 0 |
| Feb | 31 | 3 | 0.7 | 100% | 28 | 0 |
| Mar | 43 | 16 | 0.7 | 100% | 31 | 0 |
| Apr | 53 | 24 | 1.2 | 100% | 27 | 3 |
| May | 64 | 31 | 1.4 | 100% | 17 | 49 |
| Jun | 76 | 38 | 0.9 | 90% | 2 | 219 |
| Jul | 81 | 44 | 1.4 | 10% | <1 | 396 |
| Aug | 79 | 42 | 1.3 | 25% | <1 | 333 |
| Sep | 72 | 34 | 1.3 | 99% | 12 | 123 |
| Oct | 58 | 23 | 0.9 | 100% | 27 | 7 |
| Nov | 42 | 13 | 0.7 | 100% | 29 | 0 |
| Dec | 29 | 1 | 0.7 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Kremmling, CO (7,460 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, Yampa, CO, 25 miles west of Kremmling and 397 feet higher, has the same 50% last-frost date, a first frost 6 days later (September 11), a season 9 days longer.
When it snows in Kremmling, Colorado
The first measurable snow (0.1 inch or more) in Kremmling usually arrives around October 20, and the last of the season around May 3. Those are the middle dates across the winters of 1991–2020 at Kremmling, CO, 7 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 42 days after the last snow.
Planting calendar for 80459
| When | What to do |
|---|---|
| April 5 – April 19 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| April 19 – May 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| May 17 – May 31 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| June 14 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by June 13 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by August 22 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 5 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 80459 is 7 miles from Kremmling, CO, which stands at 7,460 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 80459 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°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.