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

Planting zone for 04979 — Solon, ME

ZIP code 04979 (Solon, Somerset County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 8 and the first fall frost October 5.

Where ZIP 04979 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 frostMay 8
First frostOct 5
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 Solon, 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 Solon, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 8median — 50% chance of a later frost
Safe for tender plantsMay 20only 10% chance of frost after
First fall frostOctober 5median — 10% chance by Sep 24
Growing season149 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 18.

From the NOAA station Madison, ME — 11 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 04979

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 27 – Apr 10
SpinachSow outdoors · Mar 27 – Apr 17
Broccoli, cabbageStart indoors · Feb 27 – Mar 13
Broccoli, cabbageTransplant · Apr 17 – May 1
Onion setsPlant outdoors · Apr 10 – Apr 24
PotatoesPlant outdoors · Apr 17 – May 1
LettuceSow outdoors · Apr 10 – Apr 24
Carrots, beetsSow outdoors · Apr 17 – May 1
TomatoesStart indoors · Mar 13 – Mar 27
TomatoesTransplant · May 15 – May 29
Peppers, eggplantStart indoors · Feb 27 – Mar 13
Peppers, eggplantTransplant · May 22 – Jun 5
BeansSow outdoors · May 15 – May 29
Sweet cornSow outdoors · May 15 – May 29
Cucumbers, squashSow outdoors · May 15 – May 29
Fall lettuce, spinachSow outdoors · Aug 10 – Aug 24
GarlicPlant cloves · Sep 21 – Oct 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 5) 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 04979 came on Apr 22 — 6 days earlier than the 1991–2020 average (Apr 28).

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 Maine

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

Trees 53

Shrubs 96

Wildflowers & perennials 166

Grasses 151

Vines 6

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 Solon, ME.

Soil in Solon, ME

The soil mapped at the center of ZIP 04979 is Thorndike — highly decomposed plant material, somewhat excessively drained.

TextureHighly decomposed plant materialtop layer
DrainageSomewhat excessively drainednatural drainage class
Organic matter53%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Thorndike silt loam, 3 to 15 percent slopes, very rocky.

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 04979; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Solon, ME

Summer high79 °Faverage high, July
Winter low6 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights172nights a year at 32 °F or less
Growing degree days1,941base 50 °F — the season’s usable heat
Longest day15 h 37 mindaylight on June 21
Shortest day8 h 46 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 27 °F, low 6 °F 27°6° JanFebruary: average high 30 °F, low 6 °F 30°6° FebMarch: average high 39 °F, low 17 °F 39°17° MarApril: average high 51 °F, low 30 °F 51°30° AprMay: average high 64 °F, low 42 °F 64°42° MayJune: average high 73 °F, low 52 °F 73°52° JunJuly: average high 79 °F, low 57 °F 79°57° JulAugust: average high 78 °F, low 55 °F 78°55° AugSeptember: average high 70 °F, low 47 °F 70°47° SepOctober: average high 57 °F, low 37 °F 57°37° OctNovember: average high 44 °F, low 27 °F 44°27° NovDecember: average high 33 °F, low 15 °F 33°15° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.16 in precipitation 3.2 JanFebruary: 2.30 in precipitation 2.3 FebMarch: 3.09 in precipitation 3.1 MarApril: 3.73 in precipitation 3.7 AprMay: 3.67 in precipitation 3.7 MayJune: 4.59 in precipitation 4.6 JunJuly: 4.56 in precipitation 4.6 JulAugust: 4.28 in precipitation 4.3 AugSeptember: 3.59 in precipitation 3.6 SepOctober: 4.87 in precipitation 4.9 OctNovember: 4.10 in precipitation 4.1 NovDecember: 4.22 in precipitation 4.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Madison, ME (11 mi away); precipitation: Bingham Wyman Dam, ME (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

Maine planting zones →

Questions about 04979

What planting zone is ZIP code 04979?

ZIP code 04979 (Solon, ME) 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 Solon, ME?

The median last spring frost (32 °F) near 04979 is May 8; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Madison station.

When is the first frost in Solon, ME?

The median first fall frost near 04979 is October 5, giving a median frost-free growing season of 149 days.

When should I plant tomatoes in 04979?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 04979 get?

About 46.2 inches of precipitation a year (NOAA 1991–2020 normals, Bingham Wyman Dam station).

How hot do summers get in Solon, ME?

The average high peaks at 79 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 04979 have?

The USDA soil survey maps Thorndike at the center of ZIP 04979: highly decomposed plant material, somewhat excessively drained.

Did spring come early in Solon, ME in 2026?

Spring leaf-out near 04979 came on Apr 22 in 2026, 6 days earlier than the 1991–2020 average (Apr 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Solon, ME?

Long-day onions: the longest day near 04979 is 15 h 37 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 04979 change?

Yes. The 2012 USDA map put 04979 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.