Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 55120 — Saint Paul, MN

ZIP code 55120 (Saint Paul, Dakota County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 25 and the first fall frost October 12.

Where ZIP 55120 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 25
First frostOct 12
2012 zone4b

Was 4b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Saint Paul, MN…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Saint Paul, MN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 25median — 50% chance of a later frost
Safe for tender plantsMay 9only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Oct 1
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around October 23.

From the NOAA station St Paul 3sw, MN — 4 miles away, elevation 925 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 55120

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 14 – Mar 28
SpinachSow outdoors · Mar 14 – Apr 4
Broccoli, cabbageStart indoors · Feb 14 – Feb 28
Broccoli, cabbageTransplant · Apr 4 – Apr 18
Onion setsPlant outdoors · Mar 28 – Apr 11
PotatoesPlant outdoors · Apr 4 – Apr 18
LettuceSow outdoors · Mar 28 – Apr 11
Carrots, beetsSow outdoors · Apr 4 – Apr 18
TomatoesStart indoors · Feb 28 – Mar 14
TomatoesTransplant · May 2 – May 16
Peppers, eggplantStart indoors · Feb 14 – Feb 28
Peppers, eggplantTransplant · May 9 – May 23
BeansSow outdoors · May 2 – May 16
Sweet cornSow outdoors · May 2 – May 16
Cucumbers, squashSow outdoors · May 2 – May 16
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 12) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 55120 came on Apr 3 — 12 days earlier than the 1991–2020 average (Apr 15).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 5a in Minnesota

521 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 47

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °F

Shrubs 92

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 201

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 164

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbasin wildrye5 ft · blooms early spring · high shade tolerance · to −43 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Saint Paul, MN.

Soil in Saint Paul, MN

The soil mapped at the center of ZIP 55120 is Crystal Lake — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Crystal Lake silt loam, 1 to 8 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 55120; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saint Paul, MN

Summer high82 °Faverage high, July
Winter low7 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights147nights a year at 32 °F or less
Growing degree days2,709base 50 °F — the season’s usable heat
Longest day15 h 36 mindaylight on June 21
Shortest day8 h 47 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation31.6 inper year, rain and melted snow
Snowfall51 inper year; 90 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 23 °F, low 7 °F 23°7° JanFebruary: average high 28 °F, low 12 °F 28°12° FebMarch: average high 41 °F, low 23 °F 41°23° MarApril: average high 55 °F, low 37 °F 55°37° AprMay: average high 68 °F, low 48 °F 68°48° MayJune: average high 77 °F, low 59 °F 77°59° JunJuly: average high 82 °F, low 64 °F 82°64° JulAugust: average high 79 °F, low 62 °F 79°62° AugSeptember: average high 72 °F, low 52 °F 72°52° SepOctober: average high 58 °F, low 38 °F 58°38° OctNovember: average high 41 °F, low 26 °F 41°26° NovDecember: average high 28 °F, low 14 °F 28°14° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 0.89 in precipitation, 11 in snowfall 0.9❄11 JanFebruary: 0.87 in precipitation, 9.5 in snowfall 0.9❄10 FebMarch: 1.68 in precipitation, 8.2 in snowfall 1.7❄8 MarApril: 2.91 in precipitation, 3.5 in snowfall 2.9❄4 AprMay: 3.91 in precipitation 3.9 MayJune: 4.58 in precipitation 4.6 JunJuly: 4.06 in precipitation 4.1 JulAugust: 4.34 in precipitation 4.3 AugSeptember: 3.02 in precipitation 3.0 SepOctober: 2.58 in precipitation, 0.8 in snowfall 2.6❄1 OctNovember: 1.61 in precipitation, 6.8 in snowfall 1.6❄7 NovDecember: 1.17 in precipitation, 11.4 in snowfall 1.2❄11 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: St Paul 3sw, MN (4 mi away); precipitation: Minneapolis/St Paul Airport, MN (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

551505a
Mendota, MN · <1 mi
551215a
Saint Paul, MN · 2 mi
551115a
Saint Paul, MN · 2 mi
551165a
Saint Paul, MN · 3 mi
551185a
Saint Paul, MN · 3 mi
554505a
Minneapolis, MN · 4 mi
554255a
Minneapolis, MN · 4 mi
551025a
Saint Paul, MN · 4 mi

All 36 ZIP codes in Saint Paul → · Minnesota planting zones →

Questions about 55120

What planting zone is ZIP code 55120?

ZIP code 55120 (Saint Paul, MN) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Saint Paul, MN?

The median last spring frost (32 °F) near 55120 is April 25; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, St Paul 3sw station.

When is the first frost in Saint Paul, MN?

The median first fall frost near 55120 is October 12, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 55120?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 55120 get?

About 31.6 inches of precipitation a year and 51 inches of snowfall (NOAA 1991–2020 normals, Minneapolis/St Paul Airport station).

How hot do summers get in Saint Paul, MN?

The average high peaks at 82 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 55120 have?

The USDA soil survey maps Crystal Lake at the center of ZIP 55120: silt loam, moderately well drained, pH about 5.9 (moderately acidic).

Did spring come early in Saint Paul, MN in 2026?

Spring leaf-out near 55120 came on Apr 3 in 2026, 12 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Saint Paul, MN?

Long-day onions: the longest day near 55120 is 15 h 36 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 55120 change?

Yes. The 2012 USDA map put 55120 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.