USDA Hardiness Zone 4a
Frost Dates for 55779 — Saginaw, Minnesota
NOAA 1991–2020 normals from Duluth NWS, MN (1,433 ft), 12 miles southeast.
Updated
In Saginaw, the last spring frost (32°F) is around May 18 in half of years and has passed by June 3 in nine years out of ten. The first fall frost comes around October 1, as early as September 19 one year in ten, leaving a typical freeze-free season of 135 days (NOAA, Duluth NWS, MN).
- Last spring frost
- May 18
- First fall frost
- October 1
- Growing season
- 135 days
- Hardiness zone
- 4a
50% probability
50% probability
freeze-free, 50%
-30 to -25°F (-34.4 to -31.7°C) coldest night
- First snow
- October 25
- Last snow
- April 27
- Winters with snow
- 100%
- Snow per year
- 90.2"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Saginaw
Half of springs at Duluth NWS, MN see their last 32°F night by May 18; only one in ten is past it by May 2, and one in ten still has one after June 3. Planting tender crops after May 26 leaves a 30% risk of a frost on them, after May 30 20%, and after June 3 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 77% of the 142 Minnesota 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 19 one year in ten, and holds off past October 14 one year in ten. A hard freeze of 28°F follows 11 days later, around October 12; in spring the one-in-ten date for 28°F is May 21, 13 days before the 32°F one. The freeze-free season lasts 135 days in a typical year, shorter than at 87% of the 142 Minnesota stations; it reaches 155 days one year in ten and falls short of 113 one year in ten. On average 184 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 14 days longer, to about June 1, and return around September 22. Severe cold of 16°F or below comes every winter, usually between November 11 and April 5.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 16 | May 23 | May 27 | May 30 | Jun 1 | Jun 3 | Jun 6 | Jun 11 | Jun 17 |
| 32°F | May 2 | May 7 | May 11 | May 15 | May 18 | May 22 | May 26 | May 30 | Jun 3 |
| 28°F | Apr 22 | Apr 26 | Apr 29 | May 1 | May 4 | May 7 | May 10 | May 16 | May 21 |
| 24°F | Apr 10 | Apr 15 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 2 | May 8 |
| 20°F | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 23 | Apr 28 |
| 16°F | Mar 22 | Mar 29 | Apr 1 | Apr 3 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 8 | Sep 14 | Sep 17 | Sep 20 | Sep 22 | Sep 24 | Sep 27 | Sep 30 | Oct 4 |
| 32°F | Sep 19 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 14 |
| 28°F | Sep 29 | Oct 2 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 19 | Oct 22 | Oct 27 |
| 24°F | Oct 10 | Oct 15 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 7 |
| 20°F | Oct 21 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 11 | Nov 16 |
| 16°F | Oct 31 | Nov 2 | Nov 6 | Nov 8 | Nov 11 | Nov 13 | Nov 15 | Nov 18 | Nov 23 |
Freeze probabilities 1991–2020 at Duluth NWS, 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 55779 →Compare Saginaw with another place →
Compared with the next station
The nearest other station, Duluth, MN, 12 miles southeast of Saginaw, has a last frost 5 days earlier (May 13), the same first-frost date, a season 5 days longer.
When it snows in Saginaw, Minnesota
The first measurable snow (0.1 inch or more) in Saginaw usually arrives around October 25, and the last of the season around April 27. Those are the middle dates across the winters of 1991–2020 at Duluth, MN, 12.3 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 21 days after the last snow.
Planting calendar for 55779
| When | What to do |
|---|---|
| March 9 – March 23 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 23 – April 6 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 20 – May 4 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 18 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 55779 is 12 miles from Duluth NWS, MN, which stands at 1,433 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 55810 (Proctor). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55779 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°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.