Cornish, ME frost dates
How Cornish compares
- In 8 years out of 10, the last spring frost in Cornish falls between May 1 and May 25, a 24-day window. The first fall frost falls between September 19 and October 12.
- The median last frost is 6 days later than the Maine median of May 6.
- Its 142-day growing season is longer than 22% of the 457 Maine places with a regular frost season (state median 154 days).
- The last frost is 9 days later 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 185 nights a year at or below 32°F.
- Compared with Portland, ME, 44 km away, the last frost here is 16 days later than there and the growing season is 30 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 1 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | May 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 19 |
| 50% (median) | October 1 |
| 90% (late) | October 12 |
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 Cornish, ME
Cornish, ME frost dates — last frost May 12, first frost Oct 1, zone 5a. whenisthelastfrost.com
When to plant vegetables in Cornish, ME
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Aug 6 – Sep 3 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 23 – Aug 13 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 25 – Jul 16 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 25 – Jul 16 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 25 – Jul 16 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 9 – Jul 30 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 6 – Aug 27 |
| Radishes | — | — | Apr 7 – May 19 | Aug 20 – Sep 10 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 16 – Jul 30 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 23 – Aug 6 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 9 – Jul 23 |
| Beets | — | — | Apr 21 – May 19 | Jul 23 – Aug 6 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 23 – Aug 6 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 6 – Aug 27 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 16 – Jul 30 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 17 – Oct 22 |
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 East Hiram, ME weather station, 11 km away (elevation 528 ft (161 m)).
Frost dates near Cornish
- West Baldwin May 12 · Oct 1
- East Parsonsfield May 14 · Sep 30
- Limerick May 14 · Sep 30
- Limington May 7 · Oct 4
- Hiram May 12 · Oct 1
- Steep Falls May 7 · Oct 4
- Parsonsfield May 12 · Oct 1
- East Baldwin May 12 · Oct 1
- Porter May 12 · Oct 1
- Sebago May 12 · Oct 1
Frequently asked questions
When is the last frost in Cornish, ME?
The median last spring frost in Cornish, ME is May 12. There is still about a 10% chance of frost after May 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Cornish, ME?
The median first fall frost is October 1, with about a 10% chance of frost before September 19.
How long is the growing season in Cornish, ME?
About 142 days between the median last spring frost and first fall frost.
What planting zone is Cornish, ME?
Cornish, ME is in USDA hardiness zone 5a.