Frost dates for 01550Southbridge, MA
The average last spring frost in Southbridge is May 1 and the average first fall frost is October 10, giving a typical growing season of about 162 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 10
- Growing season
- 162 days
Safer after May 13 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 181 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 1 · May 12 · May 24 | Sep 20 · Oct 2 · Oct 14 | 142 days | 100% |
| Frost / freeze (32°F) | Apr 21 · May 1 · May 13 | Sep 28 · Oct 10 · Oct 27 | 162 days | 100% |
| Hard freeze (28°F) | Apr 6 · Apr 19 · May 1 | Oct 4 · Oct 22 · Nov 6 | 185 days | 100% |
Planting calendar for Southbridge
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 20 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 30 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 23 |
| Sweet corn | Sow outdoors | May 17 – Jun 20 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 10 – Jun 20 |
| Broccoli | Transplant outdoors (fall) | Jul 10 – Jul 21 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 31 – Jun 30 |
| Cabbage | Transplant outdoors (fall) | Jun 30 – Jul 31 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 30 – Aug 16 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 17 – Aug 21 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 30 – Aug 31 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 23 – Jul 31 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 31 – Jul 16 |
| Garlic | Plant outdoors (fall) | Sep 30 – Oct 31 |
Where these dates come from
ZIP code 01550 is matched to the NOAA station Buffumville Lake, MA, 11.5 km away, at 520 ft elevation (21 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Buffumville Lake, MA (used) | 520 ft | May 1 | Oct 10 |
| Southbridge 3 Sw, MA | 685 ft | Apr 25 | Oct 13 |
| E Brimfield Lake, MA | 700 ft | Apr 28 | Oct 15 |
| W Thompson Lake, CT | 360 ft | May 1 | Oct 9 |
Frost dates near Southbridge
- Sturbridge, MA 01566 · last Apr 28, first Oct 15
- Fiskdale, MA 01518 · last Apr 28, first Oct 15
- Charlton City, MA 01508 · last Apr 28, first Oct 15
- Charlton, MA 01507 · last Apr 23, first Oct 21
- Fabyan, CT 06245 · last May 1, first Oct 9
- Quinebaug, CT 06262 · last May 1, first Oct 9
- Holland, MA 01521 · last Apr 28, first Oct 15
- East Woodstock, CT 06244 · last May 1, first Oct 9
Frequently asked questions
- When is the last frost in Southbridge, MA?
- For ZIP code 01550, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Buffumville Lake, MA weather station. There is a 1-in-10 chance of a frost after May 13.
- When is the first frost in Southbridge, MA?
- The average first fall frost (32°F) is October 10. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 01550?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 162 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.