USDA Hardiness Zone 5b
Frost Dates for 80135 — Sedalia, Colorado
NOAA 1991–2020 normals from Roxborough Sp, CO (6,117 ft), 6 miles north.
Updated
In Sedalia, the last spring frost (32°F) is around May 16 in half of years and has passed by June 1 in nine years out of ten. The first fall frost comes around October 1, as early as September 17 one year in ten, leaving a typical freeze-free season of 136 days (NOAA, Roxborough Sp, CO).
- Last spring frost
- May 16
- 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 21
- Last snow
- May 1
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
23 of 23 observed
NOAA normal
Frost risk by date in Sedalia
Half of springs at Roxborough Sp, CO see their last 32°F night by May 16; only one in ten is past it by May 2, and one in ten still has one after June 1. Planting tender crops after May 22 leaves a 30% risk of a frost on them, after May 26 20%, and after June 1 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 October 1 in half of years, as early as September 17 one year in ten, and holds off past October 15 one year in ten. A hard freeze of 28°F follows 10 days later, around October 11; in spring the one-in-ten date for 28°F is May 20, 12 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 156 days one year in ten and falls short of 115 one year in ten. On average 165 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 29, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 7 and March 31.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 14 | May 18 | May 23 | May 26 | May 29 | Jun 1 | Jun 3 | Jun 7 | Jun 12 |
| 32°F | May 2 | May 7 | May 11 | May 14 | May 16 | May 20 | May 22 | May 26 | Jun 1 |
| 28°F | Apr 20 | Apr 27 | Apr 30 | May 2 | May 5 | May 8 | May 11 | May 15 | May 20 |
| 24°F | Apr 5 | Apr 12 | Apr 18 | Apr 22 | Apr 25 | Apr 28 | May 1 | May 5 | May 10 |
| 20°F | Mar 22 | Mar 31 | Apr 4 | Apr 7 | Apr 11 | Apr 15 | Apr 20 | Apr 24 | Apr 30 |
| 16°F | Mar 8 | Mar 15 | Mar 21 | Mar 26 | Mar 31 | Apr 3 | Apr 8 | Apr 12 | Apr 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 10 | Sep 15 | Sep 18 | Sep 21 | Sep 24 | Sep 26 | Sep 29 | Oct 1 | Oct 5 |
| 32°F | Sep 17 | Sep 23 | Sep 27 | Sep 30 | Oct 1 | Oct 4 | Oct 6 | Oct 10 | Oct 15 |
| 28°F | Sep 27 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 18 | Oct 22 | Oct 26 |
| 24°F | Oct 5 | Oct 10 | Oct 15 | Oct 19 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 6 |
| 20°F | Oct 15 | Oct 20 | Oct 24 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 14 |
| 16°F | Oct 22 | Oct 28 | Nov 1 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
Freeze probabilities 1991–2020 at Roxborough Sp, 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 80135 →Compare Sedalia with another place →
Weather by month in Sedalia
July is the warmest month at Roxborough Sp, CO, averaging 85°F by day and 58°F at night; December is the coldest at 46°F and 18°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 10% of years.
Warmth for growing adds up to 2,554 growing degree days a year (base 50°F), more than at 53% of the 110 Colorado stations. 28% of them (719) have built up by the end of June, and July adds the most, 675.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 46 | 19 | 100% | 28 | 3 |
| Feb | 46 | 19 | 100% | 26 | 4 |
| Mar | 54 | 26 | 100% | 24 | 20 |
| Apr | 59 | 32 | 100% | 17 | 55 |
| May | 68 | 41 | 91% | 6 | 199 |
| Jun | 79 | 50 | 10% | <1 | 438 |
| Jul | 85 | 58 | 0% | 0 | 675 |
| Aug | 83 | 57 | 0% | 0 | 626 |
| Sep | 77 | 48 | 43% | 2 | 386 |
| Oct | 65 | 36 | 100% | 12 | 121 |
| Nov | 54 | 26 | 100% | 22 | 23 |
| Dec | 46 | 18 | 100% | 28 | 3 |
Monthly normals 1991–2020 at Roxborough Sp, CO (6,117 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, Castle Rock, CO, 9 miles northeast of Sedalia, has a last frost 7 days earlier (May 9), a first frost 1 day later (October 2), a season 7 days longer.
When it snows in Sedalia, Colorado
The first measurable snow (0.1 inch or more) in Sedalia usually arrives around October 21, and the last of the season around May 1. Those are the middle dates across the winters of 1991–2020 at Roxborough Sp, CO, 6.1 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 15 days after the last snow.
Planting calendar for 80135
| When | What to do |
|---|---|
| March 7 – March 21 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 21 – April 4 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 18 – May 2 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 16 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 80135 is 6 miles from Roxborough Sp, CO, which stands at 6,117 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 80135 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.