Frost dates for 05819Saint Johnsbury, VT
The average last spring frost in Saint Johnsbury is May 10 and the average first fall frost is October 3, giving a typical growing season of about 147 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Oct 3
- Growing season
- 147 days
Safer after May 23 (1-in-10 risk)
Possible by Sep 21 (1-in-10 risk)
Last frost typically in 190 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 8 · May 22 · Jun 4 | Sep 10 · Sep 23 · Oct 4 | 123 days | 100% |
| Frost / freeze (32°F) | Apr 27 · May 10 · May 23 | Sep 21 · Oct 3 · Oct 17 | 147 days | 100% |
| Hard freeze (28°F) | Apr 16 · Apr 27 · May 10 | Oct 2 · Oct 15 · Nov 2 | 171 days | 100% |
Planting calendar for Saint Johnsbury
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 9 – Jun 15 |
| Tomatoes | Transplant outdoors | May 26 – Jun 13 |
| Peppers | Start seeds indoors | Apr 9 – May 10 |
| Peppers | Transplant outdoors | Jun 9 – Jul 10 |
| Eggplant | Start seeds indoors | Apr 26 – May 25 |
| Eggplant | Transplant outdoors | Jun 9 – Jul 10 |
| Cucumbers | Sow outdoors | Jun 9 – Jun 23 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 16 |
| Sweet corn | Sow outdoors | May 26 – Jun 13 |
| Watermelon & cantaloupe | Sow outdoors | Jun 9 – Jul 10 |
| Okra | Sow outdoors | Jun 2 – Jun 25 |
| Peas | Sow outdoors (spring) | Apr 9 – May 25 |
| Potatoes | Plant outdoors (spring) | Apr 9 – Jun 9 |
| Onions | Start seeds indoors (spring) | Feb 26 – Mar 25 |
| Onions | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (spring) | Mar 22 – Apr 25 |
| Broccoli | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (fall) | Jun 3 – Jun 13 |
| Broccoli | Transplant outdoors (fall) | Jul 3 – Jul 14 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 24 – Jun 23 |
| Cabbage | Transplant outdoors (fall) | Jun 23 – Jul 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 23 – Aug 9 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 10 – Aug 14 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 23 – Aug 24 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 16 – Jul 24 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 24 – Jul 9 |
| Garlic | Plant outdoors (fall) | Sep 23 – Oct 24 |
Where these dates come from
ZIP code 05819 is matched to the NOAA station Saint Johnsbury, VT, 1.4 km away, at 700 ft elevation (45 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Saint Johnsbury, VT (used) | 700 ft | May 10 | Oct 3 |
| Saint Johnsbury, VT | 700 ft | May 13 | Oct 3 |
| Sutton, VT | 1,500 ft | May 9 | Oct 1 |
| E Haven, VT | 1,000 ft | May 30 | Sep 16 |
Frost dates near Saint Johnsbury
- Saint Johnsbury Center, VT 05863 · last May 10, first Oct 3
- East Saint Johnsbury, VT 05838 · last May 13, first Oct 3
- Passumpsic, VT 05861 · last May 13, first Oct 3
- Lower Waterford, VT 05848 · last May 24, first Sep 18
- Danville, VT 05828 · last May 9, first Oct 1
- Lyndon, VT 05849 · last Jun 1, first Sep 13
- Mc Indoe Falls, VT 05050 · last May 4, first Oct 5
- Concord, VT 05824 · last May 27, first Sep 19
Frequently asked questions
- When is the last frost in Saint Johnsbury, VT?
- For ZIP code 05819, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the Saint Johnsbury, VT weather station. There is a 1-in-10 chance of a frost after May 23.
- When is the first frost in Saint Johnsbury, VT?
- The average first fall frost (32°F) is October 3. 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 05819?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 147 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.