In Concord, NH, the average last spring frost is May 8 and the average first fall frost is Oct 3, which leaves about 146 frost-free days for the garden. These dates come from NOAA climate normals for the Concord Muni Airport, NH weather station, at 346 feet above sea level.
A moderate season leaves room for most vegetables. Start warm-season crops indoors for a head start, plant cool-season crops early and again in late summer, and keep row cover ready for surprise frosts. Frost timing varies from year to year: in about 1 spring in 10 the last frost falls as late as May 22, and in about 1 fall in 10 the first frost arrives as early as Sep 21.
Frost dates for Concord, NH
| Chance of a freeze (32°F) after or before this date | Last spring frost | First fall frost | Freeze-free season |
|---|---|---|---|
| Optimistic (about 1 year in 10) | Apr 27 | Oct 16 | 172 days |
| Average (half of years) | May 8 | Oct 3 | 146 days |
| Cautious (9 years in 10 are safe) | May 22 | Sep 21 | 122 days |
Source: NOAA NCEI U.S. Climate Normals, 1991 to 2020. Use the cautious dates for tender crops such as tomatoes and peppers.
When to plant in Concord, NH
These windows count weeks forward and back from the average frost dates above. They are planning guides: check the forecast before planting tender crops, and see our what to plant now tool for today's date.
| Crop | Start seeds indoors | Plant outdoors in spring | Plant in fall |
|---|---|---|---|
| Tomatoes | Mar 13 to Mar 27 | May 15 to May 22 | – |
| Peppers | Feb 27 to Mar 13 | May 22 to May 29 | – |
| Eggplant | Feb 27 to Mar 13 | May 22 to May 29 | – |
| Onions | Feb 27 to Mar 13 | Apr 10 to Apr 24 | – |
| Parsley | Feb 27 to Mar 13 | May 8 to May 15 | – |
| Broccoli, cabbage, cauliflower | Mar 13 to Mar 27 | Apr 24 to May 1 | Jul 11 to Aug 8 |
| Basil | Mar 27 to Mar 27 | May 15 to May 22 | – |
| Peas | Sow outdoors | Mar 27 to Apr 10 | Jul 11 to Aug 8 |
| Spinach | Sow outdoors | Mar 27 to Apr 10 | Aug 8 to Sep 5 |
| Radishes | Sow outdoors | Mar 27 to Apr 10 | Aug 8 to Sep 5 |
| Lettuce | Sow outdoors | Apr 10 to Apr 24 | Aug 8 to Sep 5 |
| Carrots | Sow outdoors | Apr 10 to Apr 24 | Jul 11 to Aug 8 |
| Beets | Sow outdoors | Apr 10 to Apr 24 | Jul 11 to Aug 8 |
| Potatoes | Sow outdoors | Apr 10 to Apr 24 | – |
| Kale | Sow outdoors | Apr 10 to Apr 24 | Jul 11 to Aug 8 |
| Swiss chard | Sow outdoors | Apr 24 to May 8 | – |
| Cilantro | Sow outdoors | Apr 24 to May 8 | Aug 8 to Sep 5 |
| Dill | Sow outdoors | May 8 to May 15 | – |
| Bush beans | Sow outdoors | May 15 to May 22 | Jun 30 to Jul 14 |
| Pole beans | Sow outdoors | May 15 to May 22 | – |
| Sweet corn | Sow outdoors | May 15 to May 22 | – |
| Cucumbers | Sow outdoors | May 15 to May 22 | Jun 20 to Jul 4 |
| Zucchini and summer squash | Sow outdoors | May 15 to May 22 | Jun 30 to Jul 14 |
| Winter squash | Sow outdoors | May 15 to May 22 | – |
| Sweet potatoes (slips) | Sow outdoors | May 22 to Jun 5 | – |
| Okra | Sow outdoors | May 22 to Jun 5 | – |
A dash in the fall column means the crop is not usually planted in fall, or the season is too short.
Overnight lows this week
The National Weather Service forecast shows frost risk on: Sun 15 night (28°F), Mon 16 night (23°F), Tue 17 night (32°F), Wed 18 night (32°F), Thu 19 night (36°F), Fri 20 night (35°F). Cover tender plants before dark on those nights.
| Night | Forecast low | Frost risk |
|---|---|---|
| Sun 15 night | 28°F | Freeze |
| Mon 16 night | 23°F | Freeze |
| Tue 17 night | 32°F | Freeze |
| Wed 18 night | 32°F | Freeze |
| Thu 19 night | 36°F | Frost possible |
| Fri 20 night | 35°F | Frost possible |
| Sat 21 night | 38°F | No frost expected |
Live forecast for the station location, from the National Weather Service. For your own ZIP code, use our garden weather forecast.
More garden tools for Concord, NH
- Frost dates by ZIP code for your exact location
- What to plant now, based on today's date
- Garden weather forecast by ZIP code
- Safe transplant date calculator
Frequently asked questions
When is the last frost in Concord, NH?
The average last spring frost is May 8. A late frost as far out as May 22 happens in about 1 year in 10, so tender plants such as tomatoes and peppers are safest after that cautious date.
When is the first frost in Concord, NH?
The average first fall frost is Oct 3. It can arrive as early as Sep 21 in about 1 year in 10, so plan to harvest tender crops before then.
How long is the growing season in Concord, NH?
The average freeze-free season is about 146 days, between the average last spring frost and the average first fall frost.
Where do these dates come from?
They come from the NOAA 1991 to 2020 U.S. Climate Normals for the Concord Muni Airport, NH station. Hills, valleys, lakes and city heat can shift frost by a week or more, so compare with neighbors who garden near you.