USDA Hardiness Zone 5a
Frost Dates for 55117 — Saint Paul, Minnesota
NOAA 1991–2020 normals from U Of Mn St Paul, MN (970 ft), 4 miles west.
Updated
In Saint Paul, the last spring frost (32°F) is around April 28 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 25 one year in ten, leaving a typical freeze-free season of 162 days (NOAA, U Of Mn St Paul, MN).
- Last spring frost
- April 28
- First fall frost
- October 8
- Growing season
- 162 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 27
- Last snow
- March 24
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Saint Paul
Half of springs at U Of Mn St Paul, MN see their last 32°F night by April 28; only one in ten is past it by April 14, and one in ten still has one after May 14. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 14 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 8 in half of years, as early as September 25 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 13 days later, around October 21; in spring the one-in-ten date for 28°F is May 1, 13 days before the 32°F one. The freeze-free season lasts 162 days in a typical year, longer than at 81% of the 142 Minnesota stations; it reaches 183 days one year in ten and falls short of 142 one year in ten. On average 152 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 7, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 15 and March 25.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 25 | Apr 29 | May 2 | May 5 | May 7 | May 10 | May 13 | May 18 | May 24 |
| 32°F | Apr 14 | Apr 18 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 4 | May 7 | May 14 |
| 28°F | Apr 4 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 23 | Apr 27 | May 1 |
| 24°F | Mar 26 | Mar 31 | Apr 3 | Apr 5 | Apr 8 | Apr 10 | Apr 13 | Apr 17 | Apr 22 |
| 20°F | Mar 17 | Mar 23 | Mar 27 | Mar 30 | Apr 1 | Apr 3 | Apr 5 | Apr 8 | Apr 13 |
| 16°F | Mar 9 | Mar 14 | Mar 18 | Mar 22 | Mar 25 | Mar 28 | Mar 31 | Apr 3 | Apr 7 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 18 | Sep 22 | Sep 26 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 14 |
| 32°F | Sep 25 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 19 | Oct 22 |
| 28°F | Oct 3 | Oct 9 | Oct 14 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 4 |
| 24°F | Oct 17 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 13 |
| 20°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 23 |
| 16°F | Nov 2 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 25 | Nov 30 |
Freeze probabilities 1991–2020 at U Of Mn St Paul, 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 55117 →Compare Saint Paul with another place →
Weather by month in Saint Paul
July is the warmest month at U Of Mn St Paul, MN, averaging 81°F by day and 63°F at night; January is the coldest at 21°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 40% of years.
Warmth for growing adds up to 2,650 growing degree days a year (base 50°F), more than at 77% of the 142 Minnesota stations. 33% of them (880) have built up by the end of June, and July adds the most, 685. Precipitation totals 32.8 inches a year, most in June (4.6") and least in January (0.7"); May to September bring 65% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 21 | 6 | 0.7 | 100% | 31 | 0 |
| Feb | 27 | 9 | 0.8 | 100% | 27 | 0 |
| Mar | 39 | 22 | 1.6 | 100% | 25 | 9 |
| Apr | 55 | 36 | 3.0 | 100% | 10 | 67 |
| May | 67 | 48 | 4.2 | 40% | 1 | 268 |
| Jun | 77 | 59 | 4.6 | 0% | 0 | 536 |
| Jul | 81 | 63 | 4.6 | 0% | 0 | 685 |
| Aug | 79 | 61 | 4.5 | 0% | 0 | 614 |
| Sep | 71 | 52 | 3.3 | 23% | <1 | 364 |
| Oct | 57 | 39 | 2.9 | 98% | 7 | 99 |
| Nov | 40 | 25 | 1.5 | 100% | 22 | 9 |
| Dec | 26 | 13 | 1.1 | 100% | 30 | 0 |
Monthly normals 1991–2020 at U Of Mn St Paul, MN (970 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, Vadnais Lake, MN, 4 miles north of Saint Paul, has a last frost 5 days earlier (April 23), a first frost 12 days later (October 20), a season 15 days longer.
When it snows in Saint Paul, Minnesota
The first measurable snow (0.1 inch or more) in Saint Paul usually arrives around November 27, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Vadnais Lake, MN, 4.1 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 35 days after the last snow.
Planting calendar for 55117
| When | What to do |
|---|---|
| February 17 – March 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 3 – March 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 31 – April 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 28 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 55117 is 4 miles from U Of Mn St Paul, MN, which stands at 970 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 55117 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.