USDA Hardiness Zone 5a
Frost Dates for 69301 — Alliance, Nebraska
NOAA 1991–2020 normals from Alliance 1WNW, NE (3,994 ft), 3 miles southwest.
Updated
In Alliance, the last spring frost (32°F) is around May 11 in half of years and has passed by May 28 in nine years out of ten. The first fall frost comes around October 3, as early as September 21 one year in ten, leaving a typical freeze-free season of 144 days (NOAA, Alliance 1WNW, NE).
- Last spring frost
- May 11
- First fall frost
- October 3
- Growing season
- 144 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
- November 14
- Last snow
- April 13
- Winters with snow
- 78%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
14 of 18 observed
NOAA normal
Frost risk by date in Alliance
Half of springs at Alliance 1WNW, NE see their last 32°F night by May 11; only one in ten is past it by April 28, and one in ten still has one after May 28. Planting tender crops after May 17 leaves a 30% risk of a frost on them, after May 21 20%, and after May 28 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 97% of the 68 Nebraska stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 3 in half of years, as early as September 21 one year in ten, and holds off past October 13 one year in ten. A hard freeze of 28°F follows 9 days later, around October 12; in spring the one-in-ten date for 28°F is May 16, 12 days before the 32°F one. The freeze-free season lasts 144 days in a typical year, shorter than at 94% of the 68 Nebraska stations; it reaches 162 days one year in ten and falls short of 123 one year in ten. On average 181 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 10 days longer, to about May 21, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 3 and March 31.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 7 | May 12 | May 16 | May 18 | May 21 | May 25 | May 28 | Jun 1 | Jun 7 |
| 32°F | Apr 28 | May 2 | May 5 | May 8 | May 11 | May 14 | May 17 | May 21 | May 28 |
| 28°F | Apr 17 | Apr 21 | Apr 26 | Apr 29 | May 1 | May 3 | May 6 | May 10 | May 16 |
| 24°F | Apr 5 | Apr 10 | Apr 14 | Apr 17 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 5 |
| 20°F | Mar 24 | Mar 31 | Apr 4 | Apr 7 | Apr 10 | Apr 14 | Apr 17 | Apr 22 | Apr 27 |
| 16°F | Mar 10 | Mar 16 | Mar 22 | Mar 27 | Mar 31 | Apr 3 | Apr 7 | Apr 12 | Apr 18 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 10 | Sep 15 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Sep 30 | Oct 2 | Oct 6 |
| 32°F | Sep 21 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 7 | Oct 10 | Oct 13 |
| 28°F | Sep 30 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 14 | Oct 16 | Oct 18 | Oct 22 |
| 24°F | Oct 7 | Oct 12 | Oct 14 | Oct 17 | Oct 19 | Oct 21 | Oct 24 | Oct 26 | Oct 29 |
| 20°F | Oct 13 | Oct 17 | Oct 21 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 19 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 18 |
Freeze probabilities 1991–2020 at Alliance 1WNW, NE, 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 69301 →Compare Alliance with another place →
Weather by month in Alliance
July is the warmest month at Alliance 1WNW, NE, averaging 87°F by day and 59°F at night; January is the coldest at 38°F and 14°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 84% of years.
Warmth for growing adds up to 2,635 growing degree days a year (base 50°F), fewer than at 97% of the 68 Nebraska stations. 30% of them (778) have built up by the end of June, and July adds the most, 716.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 38 | 14 | 100% | 30 | 0 |
| Feb | 40 | 15 | 100% | 27 | 1 |
| Mar | 51 | 23 | 100% | 27 | 12 |
| Apr | 58 | 32 | 100% | 18 | 50 |
| May | 68 | 43 | 84% | 4 | 212 |
| Jun | 80 | 53 | 7% | <1 | 503 |
| Jul | 87 | 59 | 0% | 0 | 716 |
| Aug | 86 | 57 | 0% | 0 | 665 |
| Sep | 77 | 47 | 38% | 2 | 383 |
| Oct | 62 | 33 | 100% | 14 | 85 |
| Nov | 49 | 22 | 100% | 28 | 7 |
| Dec | 39 | 14 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Alliance 1WNW, NE (3,994 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, Ellsworth 15 NNE, NE, 34 miles east of Alliance, has a last frost 1 day later (May 12), a first frost 2 days earlier (October 1), a season 3 days shorter.
When it snows in Alliance, Nebraska
The first measurable snow (0.1 inch or more) in Alliance usually arrives around November 14, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Alliance 1WNW, NE, 3.1 miles away: half of years saw snow earlier, half later. Snow fell in 78% of those winters. The last 32°F night of spring typically comes 28 days after the last snow.
Planting calendar for 69301
| 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 11 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 19 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 3 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 69301 is 3 miles from Alliance 1WNW, NE, which stands at 3,994 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 69301 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.