USDA Hardiness Zone 5a
Frost Dates for 03223 — Campton, New Hampshire
NOAA 1991–2020 normals from Plymouth, NH (660 ft), 7 miles south.
Updated
In Campton, the last spring frost (32°F) is around May 20 in half of years and has passed by June 4 in nine years out of ten. The first fall frost comes around September 27, as early as September 14 one year in ten, leaving a typical freeze-free season of 128 days (NOAA, Plymouth, NH).
- Last spring frost
- May 20
- First fall frost
- September 27
- Growing season
- 128 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 18
- Last snow
- April 5
- Winters with snow
- 100%
- Snow per year
- 68.3"
median, 1991–2020
median, 1991–2020
17 of 17 observed
NOAA normal
Frost risk by date in Campton
Half of springs at Plymouth, NH see their last 32°F night by May 20; only one in ten is past it by May 6, and one in ten still has one after June 4. Planting tender crops after May 26 leaves a 30% risk of a frost on them, after May 30 20%, and after June 4 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 76% of the 51 New Hampshire stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 27 in half of years, as early as September 14 one year in ten, and holds off past October 7 one year in ten. A hard freeze of 28°F follows 9 days later, around October 6; in spring the one-in-ten date for 28°F is May 24, 11 days before the 32°F one. The freeze-free season lasts 128 days in a typical year, shorter than at 92% of the 51 New Hampshire stations; it reaches 147 days one year in ten and falls short of 110 one year in ten. On average 196 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about May 31, and return around September 15. Severe cold of 16°F or below comes every winter, usually between November 18 and March 31.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 17 | May 22 | May 26 | May 29 | May 31 | Jun 3 | Jun 5 | Jun 9 | Jun 13 |
| 32°F | May 6 | May 10 | May 14 | May 17 | May 20 | May 23 | May 26 | May 30 | Jun 4 |
| 28°F | Apr 22 | Apr 27 | May 1 | May 4 | May 7 | May 10 | May 14 | May 19 | May 24 |
| 24°F | Apr 7 | Apr 13 | Apr 17 | Apr 20 | Apr 23 | Apr 27 | Apr 30 | May 4 | May 9 |
| 20°F | Mar 27 | Apr 1 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 14 | Apr 19 | Apr 25 |
| 16°F | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Mar 31 | Apr 1 | Apr 4 | Apr 6 | Apr 11 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 1 | Sep 6 | Sep 9 | Sep 12 | Sep 15 | Sep 18 | Sep 21 | Sep 24 | Sep 28 |
| 32°F | Sep 14 | Sep 18 | Sep 21 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 7 |
| 28°F | Sep 24 | Sep 29 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 16 | Oct 22 |
| 24°F | Oct 3 | Oct 8 | Oct 12 | Oct 16 | Oct 19 | Oct 23 | Oct 28 | Nov 1 | Nov 6 |
| 20°F | Oct 17 | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 19 |
| 16°F | Nov 2 | Nov 7 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Nov 27 | Dec 1 |
Freeze probabilities 1991–2020 at Plymouth, NH, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 03223 →Compare Campton with another place →
Weather by month in Campton
July is the warmest month at Plymouth, NH, averaging 80°F by day and 54°F at night; January is the coldest at 29°F and 7°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 16% of years.
Warmth for growing adds up to 1,837 growing degree days a year (base 50°F), fewer than at 84% of the 51 New Hampshire stations. 29% of them (529) have built up by the end of June, and July adds the most, 528. Precipitation totals 44.5 inches a year, most in October (4.6") and least in February (2.6"); May to September bring 45% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 29 | 7 | 3.2 | 100% | 31 | 0 |
| Feb | 33 | 8 | 2.6 | 100% | 28 | 0 |
| Mar | 41 | 18 | 3.2 | 100% | 30 | 1 |
| Apr | 55 | 29 | 3.3 | 100% | 22 | 23 |
| May | 67 | 39 | 3.7 | 96% | 8 | 147 |
| Jun | 75 | 49 | 4.4 | 16% | <1 | 359 |
| Jul | 80 | 54 | 4.5 | 0% | 0 | 528 |
| Aug | 79 | 52 | 3.8 | 0% | 0 | 471 |
| Sep | 72 | 45 | 3.6 | 63% | 4 | 260 |
| Oct | 58 | 34 | 4.6 | 100% | 18 | 45 |
| Nov | 46 | 25 | 3.6 | 100% | 25 | 4 |
| Dec | 34 | 15 | 4.0 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Plymouth, NH (660 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Waterville Valley Nepp, NH, 8 miles northeast of Campton and 769 feet higher, has a last frost 5 days earlier (May 15), a first frost 1 day later (September 28), a season 6 days longer.
When it snows in Campton, New Hampshire
The first measurable snow (0.1 inch or more) in Campton usually arrives around November 18, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Plymouth, NH, 7.2 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 45 days after the last snow.
Planting calendar for 03223
| When | What to do |
|---|---|
| March 11 – March 25 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 25 – April 8 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 22 – May 6 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 20 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 5 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 13 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 27 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 03223 is 7 miles from Plymouth, NH, which stands at 660 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 03264 (Plymouth). The 2023 USDA Plant Hardiness Zone Map lists ZIP 03223 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across New Hampshire →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.