Frost dates for 06237Columbia, CT
The average last spring frost in Columbia is April 19 and the average first fall frost is October 22, giving a typical growing season of about 186 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 19
- Average first fall frost
- Oct 22
- Growing season
- 186 days
Safer after May 3 (1-in-10 risk)
Possible by Oct 6 (1-in-10 risk)
Last frost typically in 169 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) | Apr 20 · May 3 · May 16 | Sep 29 · Oct 10 · Oct 25 | 160 days | 100% |
| Frost / freeze (32°F) | Apr 7 · Apr 19 · May 3 | Oct 6 · Oct 22 · Nov 6 | 186 days | 100% |
| Hard freeze (28°F) | Mar 26 · Apr 6 · Apr 19 | Oct 19 · Nov 4 · Nov 20 | 211 days | 100% |
Planting calendar for Columbia
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 19 – May 25 |
| Tomatoes | Transplant outdoors | May 5 – Jul 2 |
| Peppers | Start seeds indoors | Mar 19 – Apr 19 |
| Peppers | Transplant outdoors | May 19 – Jun 19 |
| Eggplant | Start seeds indoors | Apr 5 – May 4 |
| Eggplant | Transplant outdoors | May 19 – Jun 19 |
| Cucumbers | Sow outdoors | May 19 – Jul 12 |
| Summer squash | Sow outdoors | May 5 – Jun 19 |
| Winter squash & pumpkins | Sow outdoors | May 19 – Jun 19 |
| Snap beans | Sow outdoors | May 5 – Aug 4 |
| Sweet corn | Sow outdoors | May 5 – Jul 2 |
| Watermelon & cantaloupe | Sow outdoors | May 19 – Jun 19 |
| Okra | Sow outdoors | May 12 – Jun 4 |
| Peas | Sow outdoors (spring) | Mar 19 – May 4 |
| Potatoes | Plant outdoors (spring) | Mar 19 – May 19 |
| Onions | Start seeds indoors (spring) | Feb 5 – Mar 4 |
| Onions | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (spring) | Mar 1 – Apr 4 |
| Broccoli | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (fall) | Jun 22 – Jul 2 |
| Broccoli | Transplant outdoors (fall) | Jul 22 – Aug 2 |
| Cabbage | Start seeds indoors (spring) | Feb 19 – Mar 19 |
| Cabbage | Transplant outdoors (spring) | Mar 19 – Apr 19 |
| Cabbage | Start seeds indoors (fall) | Jun 12 – Jul 12 |
| Cabbage | Transplant outdoors (fall) | Jul 12 – Aug 12 |
| Leaf lettuce | Sow outdoors (spring) | Mar 19 – Jun 4 |
| Leaf lettuce | Sow outdoors (fall) | Jul 12 – Aug 28 |
| Spinach | Sow outdoors (spring) | Mar 12 – Apr 25 |
| Spinach | Sow outdoors (fall) | Jul 29 – Sep 2 |
| Radishes | Sow outdoors (spring) | Mar 19 – May 9 |
| Radishes | Sow outdoors (fall) | Jul 12 – Sep 12 |
| Kale | Sow outdoors (spring) | Apr 5 – Apr 25 |
| Kale | Sow outdoors (fall) | Jul 5 – Aug 12 |
| Carrots | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Carrots | Sow outdoors (fall) | Jun 12 – Jul 28 |
| Garlic | Plant outdoors (fall) | Oct 12 – Nov 12 |
Where these dates come from
ZIP code 06237 is matched to the NOAA station Storrs, CT, 12.7 km away, at 665 ft elevation (117 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Storrs, CT (used) | 665 ft | Apr 19 | Oct 22 |
| Willimantic Windham Ap, CT | 247 ft | Apr 28 | Oct 13 |
| Hampton, CT | 490 ft | Apr 30 | Oct 15 |
| Norwich Public Utility Plt, CT | 20 ft | Apr 14 | Oct 24 |
Frost dates near Columbia
- Andover, CT 06232 · last Apr 28, first Oct 13
- Hebron, CT 06248 · last Apr 28, first Oct 13
- Willimantic, CT 06226 · last Apr 28, first Oct 13
- Lebanon, CT 06249 · last Apr 28, first Oct 13
- Amston, CT 06231 · last Apr 28, first Oct 13
- Coventry, CT 06238 · last Apr 19, first Oct 22
- Mansfield Depot, CT 06251 · last Apr 28, first Oct 13
- Mansfield Center, CT 06250 · last Apr 28, first Oct 13
Frequently asked questions
- When is the last frost in Columbia, CT?
- For ZIP code 06237, the average last spring frost (32°F) is April 19, based on NOAA 1991-2020 climate normals for the Storrs, CT weather station. There is a 1-in-10 chance of a frost after May 3.
- When is the first frost in Columbia, CT?
- The average first fall frost (32°F) is October 22. There is a 1-in-10 chance of frost by October 6, so tender plants are at risk from that point on.
- How long is the growing season in 06237?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 186 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.