When to plant in Leominster, MA
USDA Zone 6aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Leominster, Massachusetts — all computed from Leominster's nearest NOAA weather station.
Zone 6a means Leominster sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
FITCHBURG MUNI AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Leominster’s own odds, recorded at FITCHBURG MUNI AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 24 | May 9 | Apr 29 | Sep 20 | Oct 1 | Oct 13 |
| 32°F | May 13 | Apr 29 | Apr 19 | Oct 1 | Oct 11 | Oct 27 |
| 28°F | Apr 29 | Apr 16 | Apr 4 | Oct 9 | Oct 23 | Nov 5 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Leominster, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 16 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Leominster planting FAQ
When is the last spring frost in Leominster, MA?
On average, the last spring frost in Leominster is around April 29 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Leominster, MA?
Expect Leominster's first fall frost near October 11 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Leominster in?
Leominster is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Leominster?
There are roughly 165 frost-free days in Leominster (a moderate growing season), running from the average last frost around April 29 to the first fall frost near October 11.
When should I plant tomatoes in Leominster?
In Leominster, start tomato seeds indoors around March 4–March 18, then transplant seedlings outdoors around May 6 once the danger of frost has passed.
Never miss a window in Leominster
An email when it’s time to start seeds, transplant, and sow — timed to Leominster’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Fitchburg · 10 km
- Gardner · 19 km
- Hudson · 22 km
- Marlborough · 26 km
- Maynard · 28 km
- Worcester · 28 km
- Nashua · 34 km
- Framingham · 36 km
Frost dates recorded at FITCHBURG MUNI AP, 4 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Leominster, MA — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00004780. Retrieved from https://blissgarden.com/massachusetts/leominster.