USDA Hardiness Zone 5a
Frost Dates for 56013 — Blue Earth, Minnesota
NOAA 1991–2020 normals from Winnebago, MN (1,110 ft), 10 miles north.
Updated
In Blue Earth, the last spring frost (32°F) is around April 27 in half of years and has passed by May 8 in nine years out of ten. The first fall frost comes around October 10, as early as September 27 one year in ten, leaving a typical freeze-free season of 166 days (NOAA, Winnebago, MN).
- Last spring frost
- April 27
- First fall frost
- October 10
- Growing season
- 166 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 12
- Last snow
- April 2
- Winters with snow
- 100%
- Snow per year
- 47.2"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Blue Earth
Half of springs at Winnebago, MN see their last 32°F night by April 27; only one in ten is past it by April 10, and one in ten still has one after May 8. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 5 20%, and after May 8 10%. The 11 days between the even-odds date and the one-in-ten date is the narrowest of the 142 Minnesota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 10 in half of years, as early as September 27 one year in ten, and holds off past October 23 one year in ten. A hard freeze of 28°F follows 10 days later, around October 20; in spring the one-in-ten date for 28°F is April 29, 9 days before the 32°F one. The freeze-free season lasts 166 days in a typical year, longer than at 88% of the 142 Minnesota stations; it reaches 185 days one year in ten and falls short of 147 one year in ten. On average 159 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 6, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 15 and March 22.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 29 | May 1 | May 4 | May 6 | May 8 | May 10 | May 13 | May 18 |
| 32°F | Apr 10 | Apr 16 | Apr 20 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 5 | May 8 |
| 28°F | Apr 1 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 18 | Apr 22 | Apr 24 | Apr 29 |
| 24°F | Mar 21 | Mar 27 | Mar 31 | Apr 3 | Apr 6 | Apr 8 | Apr 11 | Apr 15 | Apr 21 |
| 20°F | Mar 13 | Mar 18 | Mar 22 | Mar 26 | Mar 30 | Apr 1 | Apr 4 | Apr 7 | Apr 13 |
| 16°F | Mar 8 | Mar 12 | Mar 15 | Mar 18 | Mar 22 | Mar 25 | Mar 30 | Apr 2 | Apr 6 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 19 | Sep 23 | Sep 27 | Sep 29 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 14 |
| 32°F | Sep 27 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 |
| 28°F | Oct 5 | Oct 11 | Oct 14 | Oct 18 | Oct 20 | Oct 23 | Oct 25 | Oct 29 | Nov 1 |
| 24°F | Oct 16 | Oct 21 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 20°F | Oct 26 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
| 16°F | Nov 2 | Nov 6 | Nov 9 | Nov 11 | Nov 15 | Nov 18 | Nov 21 | Nov 25 | Nov 30 |
Freeze probabilities 1991–2020 at Winnebago, 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 56013 →Compare Blue Earth with another place →
Weather by month in Blue Earth
July is the warmest month at Winnebago, MN, averaging 82°F by day and 62°F at night; January is the coldest at 23°F and 6°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 36% of years.
Warmth for growing adds up to 2,756 growing degree days a year (base 50°F), more than at 87% of the 142 Minnesota stations. 34% of them (944) have built up by the end of June, and July adds the most, 691. Precipitation totals 34.0 inches a year, most in June (5.1") and least in January (0.9"); May to September bring 62% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 23 | 6 | 0.9 | 100% | 31 | 0 |
| Feb | 28 | 10 | 1.0 | 100% | 27 | 0 |
| Mar | 40 | 23 | 1.9 | 100% | 25 | 11 |
| Apr | 56 | 36 | 3.5 | 99% | 11 | 75 |
| May | 69 | 48 | 4.5 | 36% | 1 | 291 |
| Jun | 79 | 59 | 5.1 | 0% | 0 | 567 |
| Jul | 82 | 62 | 4.2 | 0% | 0 | 691 |
| Aug | 80 | 60 | 3.9 | 0% | 0 | 614 |
| Sep | 74 | 51 | 3.5 | 19% | <1 | 386 |
| Oct | 60 | 38 | 2.7 | 99% | 10 | 110 |
| Nov | 43 | 25 | 1.6 | 100% | 23 | 12 |
| Dec | 29 | 13 | 1.2 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Winnebago, MN (1,110 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, Amboy, MN, 18 miles north of Blue Earth, has a last frost 3 days later (April 30), a first frost 3 days earlier (October 7), a season 5 days shorter.
When it snows in Blue Earth, Minnesota
The first measurable snow (0.1 inch or more) in Blue Earth usually arrives around November 12, and the last of the season around April 2. Those are the middle dates across the winters of 1991–2020 at Winnebago, MN, 9.8 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 25 days after the last snow.
Planting calendar for 56013
| When | What to do |
|---|---|
| February 16 – March 2 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 2 – March 16 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 30 – April 13 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 27 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 26 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 10 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 56013 is 10 miles from Winnebago, MN, which stands at 1,110 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 56013 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.
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.