Frost Dates for Waterbury, CT
In Waterbury, CT, the average last spring frost is around Apr 26 and the average first fall frost around Oct 16, for a growing season of about 175 days. For frost-tender plants, wait until May 9, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Meriden Markham Muni Airport, CT weather station, 11 miles away, elevation 103 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | May 9 | Oct 4 |
| 20% | May 5 | Oct 8 |
| 30% | May 1 | Oct 11 |
| 40% | Apr 29 | Oct 14 |
| 50% | Apr 26 | Oct 16 |
| 60% | Apr 23 | Oct 20 |
| 70% | Apr 20 | Oct 23 |
| 80% | Apr 17 | Oct 28 |
| 90% | Apr 11 | Nov 1 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | May 7 | Oct 6 |
| Frost / freeze (32°F) | Apr 26 | Oct 16 |
| Hard freeze (28°F) | Apr 10 | Oct 30 |
Planting calendar for Waterbury
Transplant May 3 – May 17
Transplant May 10 – May 24
Transplant May 10 – May 24
Transplant May 3 – May 17
Sow or transplant May 3 – May 17
Sow or transplant May 3 – May 17
Sow or transplant May 10 – May 24
Sow or transplant Mar 29 – Apr 12
Fall sowing Aug 21 – Sep 18
Fall sowing Aug 21 – Sep 11
Fall sowing Aug 7 – Aug 21
Sow or transplant Mar 29 – Apr 12
Fall sowing Aug 7 – Sep 4
Transplant Apr 12 – Apr 26
Fall sowing Jul 24 – Aug 7
Transplant Apr 5 – Apr 19
Fall sowing Jul 24 – Aug 7
Fall sowing Jul 24 – Aug 7
Fall sowing Sep 4 – Sep 25
Fall sowing Aug 7 – Aug 21
Plant Mar 29 – Apr 12
Based on the average last frost (Apr 26) and first frost (Oct 16). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.