USDA Hardiness Zone 4b
Frost Dates for 55390 — Waverly, Minnesota
NOAA 1991–2020 normals from Delano, MN (975 ft), 10 miles east.
Updated
In Waverly, the last spring frost (32°F) is around April 30 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around October 8, as early as September 24 one year in ten, leaving a typical freeze-free season of 159 days (NOAA, Delano, MN).
- Last spring frost
- April 30
- First fall frost
- October 8
- Growing season
- 159 days
- Hardiness zone
- 4b
50% probability
50% probability
freeze-free, 50%
-25 to -20°F (-31.7 to -28.9°C) coldest night
- First snow
- November 29
- Last snow
- March 23
- Winters with snow
- 97%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
29 of 30 observed
NOAA normal
Frost risk by date in Waverly
Half of springs at Delano, MN see their last 32°F night by April 30; only one in ten is past it by April 18, and one in ten still has one after May 14. Planting tender crops after May 5 leaves a 30% risk of a frost on them, after May 9 20%, and after May 14 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 37% of the 142 Minnesota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 8 in half of years, as early as September 24 one year in ten, and holds off past October 21 one year in ten. A hard freeze of 28°F follows 11 days later, around October 19; in spring the one-in-ten date for 28°F is May 3, 11 days before the 32°F one. The freeze-free season lasts 159 days in a typical year, longer than at 74% of the 142 Minnesota stations; it reaches 180 days one year in ten and falls short of 140 one year in ten. On average 166 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 9 days longer, to about May 9, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 15 and March 29.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 28 | May 1 | May 4 | May 7 | May 9 | May 12 | May 16 | May 20 | May 25 |
| 32°F | Apr 18 | Apr 23 | Apr 26 | Apr 29 | Apr 30 | May 2 | May 5 | May 9 | May 14 |
| 28°F | Apr 6 | Apr 12 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 27 | Apr 30 | May 3 |
| 24°F | Mar 29 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 17 | Apr 21 | Apr 26 |
| 20°F | Mar 20 | Mar 26 | Mar 30 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 13 | Apr 18 |
| 16°F | Mar 12 | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Mar 31 | Apr 3 | Apr 6 | Apr 10 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 20 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 4 | Oct 6 | Oct 10 |
| 32°F | Sep 24 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 21 |
| 28°F | Oct 4 | Oct 10 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 26 | Oct 28 | Nov 1 |
| 24°F | Oct 17 | Oct 21 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 3 | Nov 7 | Nov 12 |
| 20°F | Oct 27 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 23 |
| 16°F | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 17 | Nov 20 | Nov 24 | Dec 1 |
Freeze probabilities 1991–2020 at Delano, MN, 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 55390 →Compare Waverly with another place →
Weather by month in Waverly
July is the warmest month at Delano, MN, averaging 83°F by day and 62°F at night; January is the coldest at 23°F and 4°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 49% of years.
Warmth for growing adds up to 2,592 growing degree days a year (base 50°F), more than at 69% of the 142 Minnesota stations. 33% of them (852) have built up by the end of June, and July adds the most, 693.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 23 | 4 | 100% | 31 | 0 |
| Feb | 28 | 7 | 100% | 28 | 0 |
| Mar | 40 | 21 | 100% | 27 | 7 |
| Apr | 56 | 33 | 100% | 14 | 55 |
| May | 69 | 47 | 49% | 2 | 261 |
| Jun | 78 | 57 | 0% | 0 | 529 |
| Jul | 83 | 62 | 0% | 0 | 693 |
| Aug | 80 | 59 | 0% | 0 | 608 |
| Sep | 72 | 50 | 23% | 1 | 347 |
| Oct | 58 | 37 | 99% | 10 | 86 |
| Nov | 41 | 24 | 100% | 24 | 7 |
| Dec | 28 | 12 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Delano, MN (975 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, Buffalo 2NE, MN, 11 miles northeast of Waverly, has the same 50% last-frost date, a first frost 1 day later (October 9), a season 4 days longer.
When it snows in Waverly, Minnesota
The first measurable snow (0.1 inch or more) in Waverly usually arrives around November 29, and the last of the season around March 23. Those are the middle dates across the winters of 1991–2020 at Delano, MN, 9.9 miles away: half of years saw snow earlier, half later. Snow fell in 97% of those winters. The last 32°F night of spring typically comes 38 days after the last snow.
Planting calendar for 55390
| When | What to do |
|---|---|
| February 19 – March 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 5 – March 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 2 – April 16 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 30 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 16 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 24 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 8 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 55390 is 10 miles from Delano, MN, which stands at 975 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station; its figures are presented in full for 55328 (Delano). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55390 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Minnesota →
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.