Frost dates for 06260Putnam, CT
The average last spring frost in Putnam is May 1 and the average first fall frost is October 9, giving a typical growing season of about 161 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 9
- Growing season
- 161 days
Safer after May 17 (1-in-10 risk)
Possible by Sep 30 (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 14 · May 31 | Sep 20 · Oct 1 · Oct 13 | 138 days | 100% |
| Frost / freeze (32°F) | Apr 20 · May 1 · May 17 | Sep 30 · Oct 9 · Oct 26 | 161 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 19 · May 2 | Oct 6 · Oct 21 · Nov 5 | 184 days | 100% |
Planting calendar for Putnam
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 19 |
| 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 29 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 22 |
| Sweet corn | Sow outdoors | May 17 – Jun 19 |
| 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 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 06260 is matched to the NOAA station W Thompson Lake, CT, 2.9 km away, at 360 ft elevation (6 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| W Thompson Lake, CT (used) | 360 ft | May 1 | Oct 9 |
| N Foster 1 E, RI | 630 ft | Apr 25 | Oct 19 |
| Hampton, CT | 490 ft | Apr 30 | Oct 15 |
| Southbridge 3 Sw, MA | 685 ft | Apr 25 | Oct 13 |
Frost dates near Putnam
- South Woodstock, CT 06267 · last May 1, first Oct 9
- Ballouville, CT 06233 · last May 1, first Oct 9
- Grosvenor Dale, CT 06246 · last May 1, first Oct 9
- North Grosvenordale, CT 06255 · last May 1, first Oct 9
- Pomfret, CT 06258 · last May 1, first Oct 9
- Dayville, CT 06241 · last May 1, first Oct 9
- Thompson, CT 06277 · last May 1, first Oct 9
- Rogers, CT 06263 · last May 1, first Oct 9
Frequently asked questions
- When is the last frost in Putnam, CT?
- For ZIP code 06260, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the W Thompson Lake, CT weather station. There is a 1-in-10 chance of a frost after May 17.
- When is the first frost in Putnam, CT?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 30, so tender plants are at risk from that point on.
- How long is the growing season in 06260?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 161 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.