Grand Isle, VT frost dates
Last spring frostApr 28median date
First fall frostOct 20median date
Growing season175 daysfrost-free
Hardiness zone5aZone 5a
How Grand Isle compares
- In 8 years out of 10, the last spring frost in Grand Isle falls between April 19 and May 10, a 21-day window. The first fall frost falls between October 4 and November 2.
- The median last frost is 15 days earlier than the Vermont median of May 13.
- Its 175-day growing season is among the longest of the 286 Vermont places with a regular frost season.
- The last frost is 5 days earlier than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 141 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 19 |
| 50% (median) | April 28 |
| 10% (safe for tender plants) | May 10 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 4 |
| 50% (median) | October 20 |
| 90% (late) | November 2 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Grand Isle, VT
Grand Isle, VT frost dates — last frost Apr 28, first frost Oct 20, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Feb 3 to Feb 17Transplant outside: Mar 31 to Apr 14
Start indoors: Feb 17 to Mar 3Transplant outside: May 12 to May 26
Start indoors: Feb 17 to Mar 3Transplant outside: May 12 to May 26
Start indoors: Mar 3 to Mar 17Transplant outside: May 5 to May 19
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 7 to Apr 21Sow outdoors: Mar 31 to May 5Plant for fall: Aug 25 to Sep 22
Start indoors: Mar 3 to Mar 17Transplant outside: Mar 31 to Apr 14Sow outdoors: Mar 31 to Apr 14Plant for fall: Aug 11 to Sep 1
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 14 to Apr 28Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 14 to Apr 28Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2Sow outdoors: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: May 5 to May 19
Sow outdoors: Mar 17 to Apr 7Plant for fall: Jul 28 to Aug 18
Sow outdoors: Mar 17 to Apr 7Plant for fall: Aug 25 to Sep 15
Sow outdoors: Mar 24 to May 5Plant for fall: Sep 8 to Sep 29
Start indoors: Mar 31 to Apr 7Transplant outside: May 12 to May 19Sow outdoors: May 5 to May 19Plant for fall: Aug 4 to Aug 18
Start indoors: Mar 31 to Apr 7Sow outdoors: May 5 to May 19Plant for fall: Aug 11 to Aug 25
Start indoors: Mar 31 to Apr 7Sow outdoors: May 5 to May 19
Start indoors: Mar 31 to Apr 7Transplant outside: May 12 to May 26
Sow outdoors: Apr 7 to May 5Plant for fall: Jul 28 to Aug 11
Sow outdoors: Apr 7 to May 5Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 7 to Apr 28
Sow outdoors: Apr 14 to May 12Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 14 to May 5Plant for fall: Aug 25 to Sep 15
Sow outdoors: May 5 to May 26Plant for fall: Aug 4 to Aug 18
Sow outdoors: May 5 to May 19
Transplant outside: May 12 to Jun 2
Plant for fall: Oct 6 to Nov 10
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Grand Isle, VT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 3 – Feb 17 | Mar 31 – Apr 14 | — | — |
| Peppers | Feb 17 – Mar 3 | May 12 – May 26 | — | — |
| Eggplant | Feb 17 – Mar 3 | May 12 – May 26 | — | — |
| Tomatoes | Mar 3 – Mar 17 | May 5 – May 19 | — | — |
| Lettuce | Mar 3 – Mar 17 | Apr 7 – Apr 21 | Mar 31 – May 5 | Aug 25 – Sep 22 |
| Kale | Mar 3 – Mar 17 | Mar 31 – Apr 14 | Mar 31 – Apr 14 | Aug 11 – Sep 1 |
| Broccoli | Mar 3 – Mar 17 | Apr 14 – Apr 28 | — | Jul 14 – Aug 4 |
| Cabbage | Mar 3 – Mar 17 | Apr 7 – Apr 21 | — | Jul 14 – Aug 4 |
| Cauliflower | Mar 3 – Mar 17 | Apr 14 – Apr 28 | — | Jul 14 – Aug 4 |
| Okra | Mar 17 – Mar 31 | May 19 – Jun 2 | May 19 – Jun 2 | — |
| Basil | Mar 17 – Mar 31 | May 5 – May 19 | — | — |
| Peas | — | — | Mar 17 – Apr 7 | Jul 28 – Aug 18 |
| Spinach | — | — | Mar 17 – Apr 7 | Aug 25 – Sep 15 |
| Radishes | — | — | Mar 24 – May 5 | Sep 8 – Sep 29 |
| Cucumbers | Mar 31 – Apr 7 | May 12 – May 19 | May 5 – May 19 | Aug 4 – Aug 18 |
| Zucchini & Summer Squash | Mar 31 – Apr 7 | — | May 5 – May 19 | Aug 11 – Aug 25 |
| Winter Squash & Pumpkins | Mar 31 – Apr 7 | — | May 5 – May 19 | — |
| Melons & Watermelon | Mar 31 – Apr 7 | May 12 – May 26 | — | — |
| Carrots | — | — | Apr 7 – May 5 | Jul 28 – Aug 11 |
| Beets | — | — | Apr 7 – May 5 | Aug 11 – Aug 25 |
| Potatoes | — | — | Apr 7 – Apr 28 | — |
| Swiss Chard | — | — | Apr 14 – May 12 | Aug 11 – Aug 25 |
| Cilantro | — | — | Apr 14 – May 5 | Aug 25 – Sep 15 |
| Green Beans | — | — | May 5 – May 26 | Aug 4 – Aug 18 |
| Sweet Corn | — | — | May 5 – May 19 | — |
| Sweet Potatoes | — | May 12 – Jun 2 | — | — |
| Garlic | — | — | — | Oct 6 – Nov 10 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the S Hero, VT weather station, 10 km away (elevation 112 ft (34 m)).
Frost dates near Grand Isle
- South Hero Apr 28 · Oct 20
- North Hero Apr 30 · Oct 12
- Milton Apr 28 · Oct 20
- Saint Albans Bay May 1 · Oct 12
- Isle La Motte Apr 30 · Oct 12
- Saint Albans May 1 · Oct 12
- Fairfax May 1 · Oct 12
- Fairfield May 1 · Oct 12
- Colchester May 2 · Oct 11
- Westford May 2 · Oct 11
Frequently asked questions
When is the last frost in Grand Isle, VT?
The median last spring frost in Grand Isle, VT is April 28. There is still about a 10% chance of frost after May 10, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Grand Isle, VT?
The median first fall frost is October 20, with about a 10% chance of frost before October 4.
How long is the growing season in Grand Isle, VT?
About 175 days between the median last spring frost and first fall frost.
What planting zone is Grand Isle, VT?
Grand Isle, VT is in USDA hardiness zone 5a.