USDA Hardiness Zone 5a
Frost Dates for 80461 — Leadville, Colorado
NOAA 1991–2020 normals from Twin Lakes Rsvr, CO (9,236 ft), 10 miles south.
Updated
In Leadville, the last spring frost (32°F) is around June 16 in half of years and has passed by June 29 in nine years out of ten. The first fall frost comes around September 10, as early as August 24 one year in ten, leaving a typical freeze-free season of 85 days (NOAA, Twin Lakes Rsvr, CO).
- Last spring frost
- June 16
- First fall frost
- September 10
- Growing season
- 85 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 8
- Last snow
- May 27
- Winters with snow
- 100%
- Snow per year
- 156.9"
median, 1991–2020
median, 1991–2020
18 of 18 observed
NOAA normal
Frost risk by date in Leadville
Half of springs at Twin Lakes Rsvr, CO see their last 32°F night by June 16; only one in ten is past it by June 3, and one in ten still has one after June 29. Planting tender crops after June 21 leaves a 30% risk of a frost on them, after June 25 20%, and after June 29 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 September 10 in half of years, as early as August 24 one year in ten, and holds off past September 23 one year in ten. A hard freeze of 28°F follows 13 days later, around September 23; in spring the one-in-ten date for 28°F is June 16, 13 days before the 32°F one. The freeze-free season lasts 85 days in a typical year, shorter than at 93% of the 110 Colorado stations; it reaches 104 days one year in ten and falls short of 64 one year in ten. On average 240 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between October 23 and April 24.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | Jun 3 | Jun 8 | Jun 11 | Jun 14 | Jun 16 | Jun 19 | Jun 21 | Jun 25 | Jun 29 |
| 28°F | May 17 | May 23 | May 27 | May 31 | Jun 2 | Jun 4 | Jun 7 | Jun 12 | Jun 16 |
| 24°F | May 2 | May 6 | May 9 | May 13 | May 16 | May 19 | May 23 | May 30 | Jun 3 |
| 20°F | Apr 21 | Apr 25 | Apr 29 | May 1 | May 4 | May 6 | May 9 | May 13 | May 18 |
| 16°F | Apr 9 | Apr 14 | Apr 18 | Apr 21 | Apr 24 | Apr 28 | May 1 | May 4 | May 8 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | too rare for a date | ||||||||
| 32°F | Aug 24 | Sep 1 | Sep 4 | Sep 7 | Sep 10 | Sep 14 | Sep 17 | Sep 19 | Sep 23 |
| 28°F | Sep 9 | Sep 15 | Sep 18 | Sep 20 | Sep 23 | Sep 25 | Sep 28 | Oct 1 | Oct 4 |
| 24°F | Sep 20 | Sep 25 | Sep 29 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 16 |
| 20°F | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 |
| 16°F | Oct 7 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 2 | Nov 6 |
Freeze probabilities 1991–2020 at Twin Lakes Rsvr, 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 80461 →Compare Leadville with another place →
Frost risk through the year in Leadville
In Leadville, the spring curve drops under 10% on June 29 and the fall curve passes 10% on August 24, 56 days later; that gap is shorter than at 95% of the 110 Colorado stations with frost dates. The spring risk falls from 90% to 10% over 26 days (June 3 to June 29) and the fall risk climbs from 10% to 90% over 30 days (August 24 to September 23): both ends of the season vary about as much. At Fairplay S Park Rd, CO, 17 miles east, the same gap runs from June 30 to August 21, 4 days shorter.
| Planted on | Another 32°F night | 28°F night |
|---|---|---|
| Jun 2 | over 90% | 50% |
| Jun 9 | 77% | 26% |
| Jun 1650% date | 50% | under 10% |
| Jun 23 | 25% | under 10% |
| Jun 30 | under 10% | under 10% |
| Jul 7 | under 10% | under 10% |
Weather by month in Leadville
July is the warmest month at Twin Lakes Rsvr, CO, averaging 74°F by day and 43°F at night; January is the coldest at 34°F and 5°F. A freezing night is all but certain in every month from September to June (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night.
Warmth for growing adds up to 674 growing degree days a year (base 50°F), fewer than at 96% of the 110 Colorado stations. 20% of them (138) have built up by the end of June, and July adds the most, 268. Precipitation totals 10.3 inches a year, most in July (1.7") and least in January (0.4"); May to September bring 58% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 34 | 5 | 0.4 | 100% | 31 | 0 |
| Feb | 35 | 5 | 0.6 | 100% | 28 | 0 |
| Mar | 41 | 13 | 0.7 | 100% | 31 | 0 |
| Apr | 46 | 21 | 0.8 | 100% | 29 | 0 |
| May | 58 | 30 | 0.9 | 100% | 22 | 15 |
| Jun | 70 | 37 | 0.7 | 94% | 5 | 122 |
| Jul | 74 | 43 | 1.7 | 7% | <1 | 268 |
| Aug | 71 | 42 | 1.6 | 20% | <1 | 204 |
| Sep | 65 | 35 | 1.1 | 98% | 8 | 61 |
| Oct | 53 | 26 | 0.8 | 100% | 26 | 3 |
| Nov | 42 | 17 | 0.5 | 100% | 29 | 0 |
| Dec | 34 | 8 | 0.5 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Twin Lakes Rsvr, CO (9,236 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, Fairplay S Park Rd, CO, 17 miles east of Leadville and 759 feet higher, has the same 50% last-frost date, a first frost 1 day earlier (September 9), a season 2 days shorter.
When it snows in Leadville, Colorado
The first measurable snow (0.1 inch or more) in Leadville usually arrives around October 8, and the last of the season around May 27. Those are the middle dates across the winters of 1991–2020 at Leadville Lake Co Airport, CO, 0.2 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 20 days after the last snow.
Planting calendar for 80461
| When | What to do |
|---|---|
| April 7 – April 21 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| April 21 – May 5 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| May 19 – June 2 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| June 16 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by June 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by August 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 10 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 80461 is 10 miles from Twin Lakes Rsvr, CO, which stands at 9,236 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 80461 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.