Frost dates for 05648Calais, VT
The average last spring frost in Calais is May 4 and the average first fall frost is October 5, giving a typical growing season of about 153 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 4
- Average first fall frost
- Oct 5
- Growing season
- 153 days
Safer after May 18 (1-in-10 risk)
Possible by Sep 21 (1-in-10 risk)
Last frost typically in 184 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 3 · May 17 · Jun 2 | Sep 11 · Sep 25 · Oct 8 | 128 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 4 · May 18 | Sep 21 · Oct 5 · Oct 20 | 153 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 23 · May 6 | Oct 2 · Oct 19 · Nov 3 | 178 days | 100% |
Planting calendar for Calais
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 | Apr 3 – Jun 9 |
| Tomatoes | Transplant outdoors | May 20 – Jun 15 |
| Peppers | Start seeds indoors | Apr 3 – May 4 |
| Peppers | Transplant outdoors | Jun 3 – Jul 4 |
| Eggplant | Start seeds indoors | Apr 20 – May 19 |
| Eggplant | Transplant outdoors | Jun 3 – Jul 4 |
| Cucumbers | Sow outdoors | Jun 3 – Jun 25 |
| Summer squash | Sow outdoors | May 20 – Jul 4 |
| Winter squash & pumpkins | Sow outdoors | Jun 3 – Jul 4 |
| Snap beans | Sow outdoors | May 20 – Jul 18 |
| Sweet corn | Sow outdoors | May 20 – Jun 15 |
| Watermelon & cantaloupe | Sow outdoors | Jun 3 – Jul 4 |
| Okra | Sow outdoors | May 27 – Jun 19 |
| Peas | Sow outdoors (spring) | Apr 3 – May 19 |
| Potatoes | Plant outdoors (spring) | Apr 3 – Jun 3 |
| Onions | Start seeds indoors (spring) | Feb 20 – Mar 19 |
| Onions | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (spring) | Mar 16 – Apr 19 |
| Broccoli | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (fall) | Jun 5 – Jun 15 |
| Broccoli | Transplant outdoors (fall) | Jul 5 – Jul 16 |
| Cabbage | Start seeds indoors (spring) | Mar 6 – Apr 3 |
| Cabbage | Transplant outdoors (spring) | Apr 3 – May 4 |
| Cabbage | Start seeds indoors (fall) | May 26 – Jun 25 |
| Cabbage | Transplant outdoors (fall) | Jun 25 – Jul 26 |
| Leaf lettuce | Sow outdoors (spring) | Apr 3 – Jun 19 |
| Leaf lettuce | Sow outdoors (fall) | Jun 25 – Aug 11 |
| Spinach | Sow outdoors (spring) | Mar 27 – May 10 |
| Spinach | Sow outdoors (fall) | Jul 12 – Aug 16 |
| Radishes | Sow outdoors (spring) | Apr 3 – May 24 |
| Radishes | Sow outdoors (fall) | Jun 25 – Aug 26 |
| Kale | Sow outdoors (spring) | Apr 20 – May 10 |
| Kale | Sow outdoors (fall) | Jun 18 – Jul 26 |
| Carrots | Sow outdoors (spring) | May 4 – Jun 19 |
| Carrots | Sow outdoors (fall) | May 26 – Jul 11 |
| Garlic | Plant outdoors (fall) | Sep 25 – Oct 26 |
Where these dates come from
ZIP code 05648 is matched to the NOAA station Worcester 2 W, VT, 8.8 km away, at 1,360 ft elevation (123 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Worcester 2 W, VT (used) | 1,360 ft | May 4 | Oct 5 |
| Plainfield, VT | 800 ft | May 25 | Sep 22 |
| Morrisville 4 Ssw, VT | 760 ft | May 24 | Sep 27 |
| Montpelier 2, VT | 530 ft | May 5 | Oct 9 |
Frost dates near Calais
- East Calais, VT 05650 · last May 4, first Oct 5
- Adamant, VT 05640 · last May 4, first Oct 5
- Worcester, VT 05682 · last May 4, first Oct 5
- Woodbury, VT 05681 · last May 4, first Oct 5
- Marshfield, VT 05658 · last May 25, first Sep 22
- East Montpelier, VT 05651 · last May 25, first Sep 22
- Cabot, VT 05647 · last May 25, first Sep 22
- Plainfield, VT 05667 · last May 16, first Sep 29
Frequently asked questions
- When is the last frost in Calais, VT?
- For ZIP code 05648, the average last spring frost (32°F) is May 4, based on NOAA 1991-2020 climate normals for the Worcester 2 W, VT weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Calais, VT?
- The average first fall frost (32°F) is October 5. There is a 1-in-10 chance of frost by September 21, so tender plants are at risk from that point on.
- How long is the growing season in 05648?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 153 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.