The current average 2-inch soil temperature across Maine is 63°F. Readings range from 62°F to 65°F, from 2 USDA and NOAA monitoring stations. Soil across Maine is running 4°F below the seasonal normal of 67°F for mid-August, based on 2 of 2 stations with historical records. Maine spans USDA hardiness zones 4a to 6a, cool-season grass country. Last updated August 16, 2026.
Soil across Maine averages 63°F at 2 inches, inside the cool-season band, but summer heat is ahead. Seedlings started now would establish during the hottest weeks of the year, so hold cool-season seeding for the fall window. Warm-season lawns are in their active season.
For cool-season lawns (fescue, bluegrass, ryegrass), fall is the best time to plant grass seed in Maine, with spring the second choice: fall seedlings face less weed competition and mature before summer heat. The window opens as 2-inch soil falls back through 70°F, and germination slows sharply once soil drops below 50°F, typically around October 24.
Spring is the second choice: the window opens when soil first holds 50°F and narrows as soil passes 65°F, typically by June 22.
Fall seeding also needs a stop date: new seedlings want about six weeks of growth before frost arrives. Your city page estimates the last safe seeding date from its nearest station: see when to plant in Portland, when to plant in Augusta or when to plant in Freeport. Readings current through August 16, 2026: Maine averages 63°F at 2 inches right now; the Current Planting Conditions section above reads that number against the season.
Typical dates are computed from historical 2-inch soil temperature averages at 2 monitoring stations in Maine; your own window depends on your nearest station's readings.
Historical 2-inch soil temperature normals for Maine: the median across 2 in-state stations with multi-year records. Any given year runs ahead of or behind these values; the live average at the top of this page shows where this year stands.
| Month | Average 2-inch soil temperature |
|---|---|
| January | 32°F |
| February | 32°F |
| March | 32°F |
| April | 42°F |
| May | 54°F |
| June | 64°F |
| July | 70°F |
| August | 68°F |
| September | 61°F |
| October | 52°F |
| November | 41°F |
| December | 33°F |
Grass seed germination
Grass seed germination temperatures across Maine. Soil warmth varies by location, so check a city page for the live reading and what germinates there now.
| Grass species | Seeding soil temp (2 in) | Days |
|---|---|---|
| Kentucky bluegrass | 50–65°F | 14-30 |
| Tall fescue | 50–65°F | 7-12 |
| Perennial ryegrass | 50–65°F | 5-10 |
| Fine fescue | 50–65°F | 7-14 |
| Bermudagrass | 75–90°F | 10-30 |
For root-zone timing (fertilizer, aeration, weed control), see the 4-inch soil temperature for Maine. For accumulated-heat timing, see growing degree days for Maine. For how wet the ground is versus normal, see soil moisture for Maine. See the Maine soil temperature map for the full station view.
Interpolated from the latest 4-inch readings and refreshed daily.
| Station | 2" Temp | Last Reading |
|---|---|---|
| Old Town 2 W | 62°F | 2026-08-16 |
| Limestone 4 NNW | 65°F | 2026-08-16 |
| City | ZIP | Current Temp |
|---|---|---|
| Auburn | 04210 | 67°F |
| Augusta | 04330 | 62°F |
| Bangor | 04401 | 62°F |
| Biddeford | 04005 | 67°F |
| Castine | 04420 | 62°F |
| Freeport | 04032 | 67°F |
| Lewiston | 04240 | 67°F |
| Limestone | 04750 | 65°F |
| New Portland | 04954 | 62°F |
| Orono | 04469 | 62°F |
| Portland | 04101 | 67°F |
| Scarborough | 04070 | 67°F |
| South Portland | 04106 | 67°F |
| Waterville | 04901 | 62°F |
| Westbrook | 04092 | 67°F |
Fall is the best time to overseed a thin lawn.
Core aeration relieves compaction, but timing decides whether the lawn recovers in a week or struggles for a month.
Brown patch and Pythium strike when humid nights hold above 68°F on lush, over-fertilized turf; dollar spot, red thread, and rust hit slow-growing lawns at 60-85°F.
Check whether your soil is warm enough for the seed you bought: cool-season grass seeds into 50-65°F soil (tall fescue prefers 60°F and up), warm-season into 75-85°F.
The current average 2-inch soil temperature across Maine is 63°F. Readings range from 62°F to 65°F depending on location and elevation, from 2 USDA and NOAA monitoring stations. Soil across Maine is running 4°F below the seasonal normal of 67°F for mid-August, based on 2 of 2 stations with historical records.
Apply pre-emergent herbicide when soil at 2 inches reaches 55°F for several consecutive days. Timing varies across Maine, so check your city's page for station-specific readings and the pre-emergent timing recommendation.
Maine spans USDA hardiness zones 4a to 6a, cool-season grass country. For cool-season grasses (fescue, bluegrass), the fall window typically opens around July 21 and the spring window around May 7, based on historical 2-inch soil temperature averages at 2 in-state stations. Timing varies by location, so check your city's planting window for the dates specific to your area.