Planting zone for 04442 — Greenville Junction, ME
ZIP code 04442 (Greenville Junction, Piscataquis County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 7 and the first fall frost October 9.
Where ZIP 04442 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
Was 4a 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 4b means →
Frost forecast — next 7 nights
live from the National Weather ServiceLoading the forecast for Greenville Junction, 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 Greenville Junction, ME
A hard freeze (28 °F) usually ends around April 28 and returns around October 22.
From the NOAA station Greenville Maine Forestry Svc, ME — 5 miles away, elevation 1,037 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 04442
Counted from the median last spring frost (May 7) 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 04442 came on May 5 — about the same time as the 1991–2020 average (May 7).
May 72026
May 5
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 Greenville Junction, ME
The soil mapped at the center of ZIP 04442 is Chesuncook — highly decomposed plant material, moderately well drained.
Map unit: Chesuncook-Elliottsville-Telos association, 15 to 35 percent slopes, very stony.
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 04442; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Greenville Junction, ME
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Greenville Maine Forestry Svc, ME (5 mi away); precipitation: Greenville Maine Forestry Svc, ME (5 mi away). 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.
Questions about 04442
What planting zone is ZIP code 04442?
ZIP code 04442 (Greenville Junction, ME) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).
When is the last frost in Greenville Junction, ME?
The median last spring frost (32 °F) near 04442 is May 7; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Greenville Maine Forestry Svc station.
When is the first frost in Greenville Junction, ME?
The median first fall frost near 04442 is October 9, giving a median frost-free growing season of 153 days.
When should I plant tomatoes in 04442?
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 04442 get?
About 44.5 inches of precipitation a year (NOAA 1991–2020 normals, Greenville Maine Forestry Svc station).
How hot do summers get in Greenville Junction, ME?
The average high peaks at 75 °F in July, with about 1 days a year at 90 °F or more.
What kind of soil does 04442 have?
The USDA soil survey maps Chesuncook at the center of ZIP 04442: highly decomposed plant material, moderately well drained.
Did spring come early in Greenville Junction, ME in 2026?
Spring leaf-out near 04442 came on May 5 in 2026, about the same as the 1991–2020 average (May 7), according to the USA National Phenology Network Spring Index.
What kind of onions grow in Greenville Junction, ME?
Long-day onions: the longest day near 04442 is 15 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).
Did the zone for 04442 change?
Yes. The 2012 USDA map put 04442 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.