USDA Hardiness Zone 5a
Frost Dates for 55042 — Lake Elmo, Minnesota
NOAA 1991–2020 normals from Stillwater 2SW, MN (898 ft), 4 miles northeast.
Updated
In Lake Elmo, the last spring frost (32°F) is around April 30 in half of years and has passed by May 13 in nine years out of ten. The first fall frost comes around October 11, as early as September 28 one year in ten, leaving a typical freeze-free season of 163 days (NOAA, Stillwater 2SW, MN).
- Last spring frost
- April 30
- First fall frost
- October 11
- Growing season
- 163 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 15
- Last snow
- April 3
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
15 of 15 observed
NOAA normal
Frost risk by date in Lake Elmo
Half of springs at Stillwater 2SW, MN see their last 32°F night by April 30; only one in ten is past it by April 17, and one in ten still has one after May 13. Planting tender crops after May 5 leaves a 30% risk of a frost on them, after May 8 20%, and after May 13 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 61% of the 142 Minnesota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 11 in half of years, as early as September 28 one year in ten, and holds off past October 23 one year in ten. A hard freeze of 28°F follows 12 days later, around October 23; in spring the one-in-ten date for 28°F is May 2, 11 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, longer than at 84% of the 142 Minnesota stations; it reaches 181 days one year in ten and falls short of 143 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 8 days longer, to about May 8, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 18 and March 27.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 30 | May 3 | May 6 | May 8 | May 11 | May 14 | May 18 | May 23 |
| 32°F | Apr 17 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 5 | May 8 | May 13 |
| 28°F | Apr 6 | Apr 11 | Apr 14 | Apr 17 | Apr 20 | Apr 22 | Apr 25 | Apr 28 | May 2 |
| 24°F | Mar 29 | Apr 2 | Apr 5 | Apr 7 | Apr 9 | Apr 12 | Apr 15 | Apr 20 | Apr 24 |
| 20°F | Mar 19 | Mar 24 | Mar 29 | Apr 1 | Apr 2 | Apr 4 | Apr 7 | Apr 10 | Apr 17 |
| 16°F | Mar 11 | Mar 17 | Mar 20 | Mar 24 | Mar 27 | Mar 31 | Apr 1 | Apr 4 | Apr 8 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 24 | Sep 27 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 14 |
| 32°F | Sep 28 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 16 | Oct 20 | Oct 23 |
| 28°F | Oct 10 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Oct 31 | Nov 4 |
| 24°F | Oct 19 | Oct 24 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 14 |
| 20°F | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 22 |
| 16°F | Nov 4 | Nov 8 | Nov 13 | Nov 15 | Nov 18 | Nov 20 | Nov 23 | Nov 26 | Dec 1 |
Freeze probabilities 1991–2020 at Stillwater 2SW, 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 55042 →Compare Lake Elmo with another place →
Weather by month in Lake Elmo
July is the warmest month at Stillwater 2SW, MN, averaging 79°F by day and 62°F at night; January is the coldest at 22°F and 5°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 47% of years.
Warmth for growing adds up to 2,473 growing degree days a year (base 50°F), more than at 54% of the 142 Minnesota stations. 33% of them (810) have built up by the end of June, and July adds the most, 644.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 22 | 5 | 100% | 31 | 0 |
| Feb | 28 | 8 | 100% | 28 | 0 |
| Mar | 41 | 20 | 100% | 25 | 8 |
| Apr | 55 | 34 | 100% | 13 | 56 |
| May | 67 | 47 | 47% | 1 | 246 |
| Jun | 76 | 58 | 0% | 0 | 500 |
| Jul | 79 | 62 | 0% | 0 | 644 |
| Aug | 78 | 60 | 0% | 0 | 590 |
| Sep | 71 | 51 | 15% | 0 | 339 |
| Oct | 58 | 38 | 99% | 8 | 84 |
| Nov | 41 | 25 | 100% | 23 | 5 |
| Dec | 28 | 13 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Stillwater 2SW, MN (898 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, Stillwater 1 SE, MN, 6 miles northeast of Lake Elmo and 188 feet lower, has a last frost 8 days earlier (April 22), a first frost 8 days later (October 19), a season 15 days longer.
When it snows in Lake Elmo, Minnesota
The first measurable snow (0.1 inch or more) in Lake Elmo usually arrives around November 15, and the last of the season around April 3. Those are the middle dates across the winters of 1991–2020 at Stillwater 1 SE, MN, 6.2 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 27 days after the last snow.
Planting calendar for 55042
| 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 19 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 11 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 55042 is 4 miles from Stillwater 2SW, MN, which stands at 898 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 55082 (Stillwater). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55042 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.