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

Planting zone for Augusta, ME

Augusta, ME is in USDA zone 5b across its 5 ZIP codes. The median last spring frost is April 27 and the first fall frost October 16.

Augusta on the zone map

Outlined: its 1 ZIP code areas · 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.

Zone5b−15 to −10 °F
ZIP codes5
Last frostApr 27
First frostOct 16
Growing season172 days

5b 5 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Augusta, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 27median — 50% chance of a later frost
Safe for tender plantsMay 7only 10% chance of frost after
First fall frostOctober 16median — 10% chance by Oct 2
Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 31.

From the NOAA station Augusta State Airport, ME, elevation 351 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 Augusta

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4
GarlicPlant cloves · Oct 2 – Nov 6
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 16) 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 04330 came on Apr 16 — 5 days earlier than the 1991–2020 average (Apr 21).

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 5b in Maine

493 plants native to the lower 48 states, recorded in Maine, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 55

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 98

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falpine bearberry0.5 ft · blooms early spring · medium shade tolerance · to −62 °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 °F

Wildflowers & perennials 169

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 153

alpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °F

Vines 6

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 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °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 Augusta, ME.

Soil in Augusta, ME

The soil mapped at the center of ZIP 04330 is Scantic — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables
pH6.0slightly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter6%high
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of local importanceUSDA classification

Map unit: Scantic silt loam, 0 to 3 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 04330; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Augusta, ME

Summer high80 °Faverage high, July
Winter low12 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights147nights a year at 32 °F or less
Growing degree days2,282base 50 °F — the season’s usable heat
Longest day15 h 32 mindaylight on June 21
Shortest day8 h 51 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation46.2 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 29 °F, low 12 °F 29°12° JanFebruary: average high 32 °F, low 14 °F 32°14° FebMarch: average high 41 °F, low 23 °F 41°23° MarApril: average high 54 °F, low 34 °F 54°34° AprMay: average high 66 °F, low 45 °F 66°45° MayJune: average high 74 °F, low 54 °F 74°54° JunJuly: average high 80 °F, low 60 °F 80°60° JulAugust: average high 79 °F, low 59 °F 79°59° AugSeptember: average high 71 °F, low 51 °F 71°51° SepOctober: average high 58 °F, low 40 °F 58°40° OctNovember: average high 46 °F, low 30 °F 46°30° NovDecember: average high 35 °F, low 20 °F 35°20° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.38 in precipitation 3.4 JanFebruary: 2.87 in precipitation 2.9 FebMarch: 3.40 in precipitation 3.4 MarApril: 4.25 in precipitation 4.3 AprMay: 3.41 in precipitation 3.4 MayJune: 4.24 in precipitation 4.2 JunJuly: 3.26 in precipitation 3.3 JulAugust: 3.63 in precipitation 3.6 AugSeptember: 3.94 in precipitation 3.9 SepOctober: 5.09 in precipitation 5.1 OctNovember: 4.33 in precipitation 4.3 NovDecember: 4.41 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Augusta State Airport, ME (3 mi away); precipitation: Augusta Landfill, ME (3 mi away). Daylight is calculated from latitude.

ZIP codes in Augusta

043305b
−15 to −10 °F
043325b
−15 to −10 °F
043335b
−15 to −10 °F
043365b
−15 to −10 °F
043385b
−15 to −10 °F

Maine planting zones →

Questions about Augusta

What planting zone is Augusta, ME?

Augusta, ME is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Augusta, ME?

The median last spring frost is April 27 and the median first fall frost is October 16 (NOAA 1991–2020 normals, Augusta State Airport station).

When can I plant a garden in Augusta, ME?

Cool-season crops like peas and spinach go in around Mar 16 – Apr 6; tomatoes, peppers, beans and squash after about May 4, once frost risk has passed.

What kind of onions grow in Augusta, ME?

Long-day onions: the longest day is 15 h 32 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Augusta, ME get?

About 46.2 inches of precipitation a year (NOAA 1991–2020 normals).