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

Planting zone for 04004 — Bar Mills, ME

ZIP code 04004 (Bar Mills, York County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 7 and the first fall frost October 4.

Where ZIP 04004 is

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 7
First frostOct 4
2012 zone5a

Was 5a 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 5b means →

Frost forecast — next 7 nights

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Loading the forecast for Bar Mills, 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 Bar Mills, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 7median — 50% chance of a later frost
Safe for tender plantsMay 18only 10% chance of frost after
First fall frostOctober 4median — 10% chance by Sep 23
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 26 and returns around October 13.

From the NOAA station West Buxton 2 Nnw, ME — 6 miles away, elevation 220 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 04004

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 26 – Apr 9
SpinachSow outdoors · Mar 26 – Apr 16
Broccoli, cabbageStart indoors · Feb 26 – Mar 12
Broccoli, cabbageTransplant · Apr 16 – Apr 30
Onion setsPlant outdoors · Apr 9 – Apr 23
PotatoesPlant outdoors · Apr 16 – Apr 30
LettuceSow outdoors · Apr 9 – Apr 23
Carrots, beetsSow outdoors · Apr 16 – Apr 30
TomatoesStart indoors · Mar 12 – Mar 26
TomatoesTransplant · May 14 – May 28
Peppers, eggplantStart indoors · Feb 26 – Mar 12
Peppers, eggplantTransplant · May 21 – Jun 4
BeansSow outdoors · May 14 – May 28
Sweet cornSow outdoors · May 14 – May 28
Cucumbers, squashSow outdoors · May 14 – May 28
Fall lettuce, spinachSow outdoors · Aug 9 – Aug 23
GarlicPlant cloves · Sep 20 – Oct 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 4) 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 04004 came on Apr 16 — 3 days earlier than the 1991–2020 average (Apr 19).

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).

Soil in Bar Mills, ME

The soil mapped at the center of ZIP 04004 is Scio — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH4.8strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter4%moderate
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Scio silt loam, 8 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 04004; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bar Mills, ME

Summer high82 °Faverage high, July
Winter low8 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights171nights a year at 32 °F or less
Growing degree days2,221base 50 °F — the season’s usable heat
Longest day15 h 26 mindaylight on June 21
Shortest day8 h 56 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation49.6 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 31 °F, low 8 °F 31°8° JanFebruary: average high 34 °F, low 10 °F 34°10° FebMarch: average high 43 °F, low 20 °F 43°20° MarApril: average high 56 °F, low 31 °F 56°31° AprMay: average high 67 °F, low 43 °F 67°43° MayJune: average high 76 °F, low 52 °F 76°52° JunJuly: average high 82 °F, low 58 °F 82°58° JulAugust: average high 81 °F, low 56 °F 81°56° AugSeptember: average high 73 °F, low 48 °F 73°48° SepOctober: average high 60 °F, low 36 °F 60°36° OctNovember: average high 48 °F, low 26 °F 48°26° NovDecember: average high 37 °F, low 16 °F 37°16° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.47 in precipitation 3.5 JanFebruary: 3.36 in precipitation 3.4 FebMarch: 4.25 in precipitation 4.3 MarApril: 4.69 in precipitation 4.7 AprMay: 3.80 in precipitation 3.8 MayJune: 4.34 in precipitation 4.3 JunJuly: 3.97 in precipitation 4.0 JulAugust: 3.49 in precipitation 3.5 AugSeptember: 3.92 in precipitation 3.9 SepOctober: 5.51 in precipitation 5.5 OctNovember: 4.39 in precipitation 4.4 NovDecember: 4.39 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: West Buxton 2 Nnw, ME (6 mi away); precipitation: West Buxton 2 Nnw, ME (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

040935b
Buxton, ME · 2 mi
040425b
Hollis Center, ME · 3 mi
040725b
Saco, ME · 6 mi
040385b
Gorham, ME · 7 mi
040305b
East Waterboro, ME · 8 mi
040055b
Biddeford, ME · 9 mi
040746a
Scarborough, ME · 9 mi
040615a
North Waterboro, ME · 10 mi

Maine planting zones →

Questions about 04004

What planting zone is ZIP code 04004?

ZIP code 04004 (Bar Mills, 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 Bar Mills, ME?

The median last spring frost (32 °F) near 04004 is May 7; after May 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, West Buxton 2 Nnw station.

When is the first frost in Bar Mills, ME?

The median first fall frost near 04004 is October 4, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 04004?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 04004 get?

About 49.6 inches of precipitation a year (NOAA 1991–2020 normals, West Buxton 2 Nnw station).

How hot do summers get in Bar Mills, ME?

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 04004 have?

The USDA soil survey maps Scio at the center of ZIP 04004: silt loam, moderately well drained, pH about 4.8 (strongly acidic).

Did spring come early in Bar Mills, ME in 2026?

Spring leaf-out near 04004 came on Apr 16 in 2026, 3 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bar Mills, ME?

Long-day onions: the longest day near 04004 is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 04004 change?

Yes. The 2012 USDA map put 04004 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.