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

Planting zone for 04648 — Jonesboro, ME

ZIP code 04648 (Jonesboro, Washington County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 3 and the first fall frost October 9.

Where ZIP 04648 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostMay 3
First frostOct 9
2012 zone5b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Jonesboro, ME…

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 Jonesboro, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 3median — 50% chance of a later frost
Safe for tender plantsMay 16only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 27
Growing season158 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 22 and returns around October 24.

From the NOAA station Jonesboro, ME — within 1 mile, elevation 194 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 04648

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 22 – Apr 5
SpinachSow outdoors · Mar 22 – Apr 12
Broccoli, cabbageStart indoors · Feb 22 – Mar 8
Broccoli, cabbageTransplant · Apr 12 – Apr 26
Onion setsPlant outdoors · Apr 5 – Apr 19
PotatoesPlant outdoors · Apr 12 – Apr 26
LettuceSow outdoors · Apr 5 – Apr 19
Carrots, beetsSow outdoors · Apr 12 – Apr 26
TomatoesStart indoors · Mar 8 – Mar 22
TomatoesTransplant · May 10 – May 24
Peppers, eggplantStart indoors · Feb 22 – Mar 8
Peppers, eggplantTransplant · May 17 – May 31
BeansSow outdoors · May 10 – May 24
Sweet cornSow outdoors · May 10 – May 24
Cucumbers, squashSow outdoors · May 10 – May 24
Fall lettuce, spinachSow outdoors · Aug 14 – Aug 28
GarlicPlant cloves · Sep 25 – Oct 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 3) and first fall frost (Oct 9) 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 04648 came on Apr 26 — about the same time as the 1991–2020 average (Apr 25).

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 Jonesboro, ME.

Soil in Jonesboro, ME

The soil mapped at the center of ZIP 04648 is Lamoine — moderately decomposed plant material, somewhat poorly drained.

TextureModerately decomposed plant materialtop layer
DrainageSomewhat poorly drainedconsider raised beds
Organic matter53%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Lamoine-Buxton-Scantic complex, 0 to 15 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 04648; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Jonesboro, ME

Summer high76 °Faverage high, July
Winter low9 °Faverage low, January
Hot days2days a year at 90 °F or more
Freezing nights162nights a year at 32 °F or less
Growing degree days1,741base 50 °F — the season’s usable heat
Longest day15 h 34 mindaylight on June 21
Shortest day8 h 48 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation50.8 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 9 °F 29°9° JanFebruary: average high 32 °F, low 12 °F 32°12° FebMarch: average high 39 °F, low 22 °F 39°22° MarApril: average high 51 °F, low 32 °F 51°32° AprMay: average high 61 °F, low 42 °F 61°42° MayJune: average high 70 °F, low 51 °F 70°51° JunJuly: average high 76 °F, low 56 °F 76°56° JulAugust: average high 76 °F, low 55 °F 76°55° AugSeptember: average high 69 °F, low 49 °F 69°49° SepOctober: average high 57 °F, low 39 °F 57°39° OctNovember: average high 46 °F, low 30 °F 46°30° NovDecember: average high 35 °F, low 19 °F 35°19° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 4.30 in precipitation 4.3 JanFebruary: 3.77 in precipitation 3.8 FebMarch: 4.64 in precipitation 4.6 MarApril: 4.26 in precipitation 4.3 AprMay: 3.90 in precipitation 3.9 MayJune: 3.53 in precipitation 3.5 JunJuly: 3.38 in precipitation 3.4 JulAugust: 3.59 in precipitation 3.6 AugSeptember: 3.50 in precipitation 3.5 SepOctober: 5.00 in precipitation 5.0 OctNovember: 5.07 in precipitation 5.1 NovDecember: 5.90 in precipitation 5.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Jonesboro, ME (within 1 mile); precipitation: Jonesboro, ME (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

6 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

046235b
Columbia Falls, ME · 5 mi
046545b
Machias, ME · 7 mi
046066a
Addison, ME · 9 mi
046496a
Jonesport, ME · 9 mi
046556a
Machiasport, ME · 12 mi
046436a
Harrington, ME · 12 mi
046116a
Beals, ME · 13 mi
046586a
Milbridge, ME · 16 mi

Maine planting zones →

Questions about 04648

What planting zone is ZIP code 04648?

ZIP code 04648 (Jonesboro, ME) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Jonesboro, ME?

The median last spring frost (32 °F) near 04648 is May 3; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Jonesboro station.

When is the first frost in Jonesboro, ME?

The median first fall frost near 04648 is October 9, giving a median frost-free growing season of 158 days.

When should I plant tomatoes in 04648?

Start tomato seeds indoors around Mar 8 – Mar 22 and set transplants outside around May 10 – May 24, one to three weeks after the median last frost.

How much rain and snow does 04648 get?

About 50.8 inches of precipitation a year (NOAA 1991–2020 normals, Jonesboro station).

How hot do summers get in Jonesboro, ME?

The average high peaks at 76 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 04648 have?

The USDA soil survey maps Lamoine at the center of ZIP 04648: moderately decomposed plant material, somewhat poorly drained.

Did spring come early in Jonesboro, ME in 2026?

Spring leaf-out near 04648 came on Apr 26 in 2026, about the same as the 1991–2020 average (Apr 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Jonesboro, ME?

Long-day onions: the longest day near 04648 is 15 h 34 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).