USDA Hardiness Zone 7a
Frost Dates for 88312 — Alto, New Mexico
NOAA 1991–2020 normals from Ruidoso, NM (6,930 ft), 4 miles south.
Updated
In Alto, the last spring frost (32°F) is around May 11 in half of years and has passed by May 22 in nine years out of ten. The first fall frost comes around October 5, as early as September 24 one year in ten, leaving a typical freeze-free season of 147 days (NOAA, Ruidoso, NM).
- Last spring frost
- May 11
- First fall frost
- October 5
- Growing season
- 147 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- November 15
- Last snow
- March 29
- Winters with snow
- 100%
- Snow per year
- 27.3"
median, 1991–2020
median, 1991–2020
20 of 20 observed
NOAA normal
Frost risk by date in Alto
Half of springs at Ruidoso, NM see their last 32°F night by May 11; only one in ten is past it by April 30, and one in ten still has one after May 22. Planting tender crops after May 16 leaves a 30% risk of a frost on them, after May 18 20%, and after May 22 10%. The 11 days between the even-odds date and the one-in-ten date is the narrowest of the 70 New Mexico stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 5 in half of years, as early as September 24 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 12 days later, around October 17; in spring the one-in-ten date for 28°F is May 11, 11 days before the 32°F one. The freeze-free season lasts 147 days in a typical year, shorter than at 69% of the 70 New Mexico stations; it reaches 165 days one year in ten and falls short of 129 one year in ten. On average 156 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 23, and return around September 26. Severe cold of 16°F or below comes every winter, usually between November 17 and March 17.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 11 | May 15 | May 18 | May 21 | May 23 | May 26 | May 30 | Jun 2 | Jun 5 |
| 32°F | Apr 30 | May 4 | May 6 | May 9 | May 11 | May 13 | May 16 | May 18 | May 22 |
| 28°F | Apr 15 | Apr 20 | Apr 24 | Apr 27 | Apr 30 | May 3 | May 5 | May 8 | May 11 |
| 24°F | Apr 1 | Apr 5 | Apr 9 | Apr 13 | Apr 16 | Apr 20 | Apr 23 | Apr 27 | May 2 |
| 20°F | Mar 15 | Mar 22 | Mar 28 | Apr 1 | Apr 4 | Apr 6 | Apr 10 | Apr 15 | Apr 20 |
| 16°F | Feb 19 | Mar 2 | Mar 7 | Mar 12 | Mar 17 | Mar 22 | Mar 27 | Apr 2 | Apr 6 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 12 | Sep 17 | Sep 20 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 3 | Oct 6 |
| 32°F | Sep 24 | Sep 27 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 20 |
| 28°F | Oct 3 | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 27 | Nov 1 |
| 24°F | Oct 13 | Oct 18 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 9 |
| 20°F | Oct 24 | Oct 29 | Nov 2 | Nov 4 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 21 |
| 16°F | Nov 1 | Nov 5 | Nov 10 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 27 | Dec 4 |
Freeze probabilities 1991–2020 at Ruidoso, NM, 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 88312 →Compare Alto with another place →
Weather by month in Alto
July is the warmest month at Ruidoso, NM, averaging 81°F by day and 51°F at night; January is the coldest at 49°F and 21°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 89% of years.
Warmth for growing adds up to 2,048 growing degree days a year (base 50°F), fewer than at 94% of the 70 New Mexico stations. 35% of them (714) have built up by the end of June, and July adds the most, 502. Precipitation totals 22.0 inches a year, most in July (4.3") and least in April (0.7"); May to September bring 65% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 49 | 21 | 1.1 | 100% | 27 | 0 |
| Feb | 51 | 23 | 1.0 | 100% | 24 | 2 |
| Mar | 58 | 27 | 0.9 | 100% | 24 | 9 |
| Apr | 65 | 33 | 0.7 | 100% | 15 | 55 |
| May | 73 | 40 | 1.2 | 89% | 3 | 215 |
| Jun | 82 | 47 | 2.1 | 1% | 0 | 433 |
| Jul | 81 | 51 | 4.3 | 0% | 0 | 502 |
| Aug | 79 | 50 | 4.2 | 0% | 0 | 446 |
| Sep | 75 | 44 | 2.5 | 30% | 1 | 289 |
| Oct | 67 | 35 | 1.7 | 98% | 12 | 92 |
| Nov | 56 | 26 | 0.8 | 100% | 23 | 5 |
| Dec | 48 | 22 | 1.5 | 100% | 27 | 0 |
Monthly normals 1991–2020 at Ruidoso, NM (6,930 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, Capitan, NM, 8 miles north of Alto and 450 feet lower, has a last frost 8 days earlier (May 3), a first frost 7 days later (October 12), a season 14 days longer.
When it snows in Alto, New Mexico
The first measurable snow (0.1 inch or more) in Alto usually arrives around November 15, and the last of the season around March 29. Those are the middle dates across the winters of 1991–2020 at Capitan, NM, 8 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 43 days after the last snow.
Planting calendar for 88312
| When | What to do |
|---|---|
| March 2 – March 16 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 16 – March 30 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 13 – April 27 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 11 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 13 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 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 88312 is 4 miles from Ruidoso, NM, which stands at 6,930 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 88345 (Ruidoso). The 2023 USDA Plant Hardiness Zone Map lists ZIP 88312 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across New Mexico →
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.