USDA Hardiness Zone 6a
Frost Dates for 03842 — Hampton, New Hampshire
NOAA 1991–2020 normals from Greenland, NH (95 ft), 6 miles north.
Updated
In Hampton, the last spring frost (32°F) is around May 4 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around October 8, as early as September 27 one year in ten, leaving a typical freeze-free season of 157 days (NOAA, Greenland, NH).
- Last spring frost
- May 4
- First fall frost
- October 8
- Growing season
- 157 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- December 4
- Last snow
- March 27
- Winters with snow
- 100%
- Snow per year
- 62.6"
median, 1991–2020
median, 1991–2020
16 of 16 observed
NOAA normal
Frost risk by date in Hampton
Half of springs at Greenland, NH see their last 32°F night by May 4; only one in ten is past it by April 23, and one in ten still has one after May 18. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 14 20%, and after May 18 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 25% of the 51 New Hampshire stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 8 in half of years, as early as September 27 one year in ten, and holds off past October 24 one year in ten. A hard freeze of 28°F follows 13 days later, around October 21; in spring the one-in-ten date for 28°F is May 7, 11 days before the 32°F one. The freeze-free season lasts 157 days in a typical year, longer than at 69% of the 51 New Hampshire stations; it reaches 174 days one year in ten and falls short of 138 one year in ten. On average 143 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 12 days longer, to about May 16, and return around September 30. Severe cold of 16°F or below comes every winter, usually between December 1 and March 16.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 3 | May 7 | May 10 | May 13 | May 16 | May 19 | May 22 | May 25 | May 29 |
| 32°F | Apr 23 | Apr 27 | Apr 29 | May 2 | May 4 | May 7 | May 10 | May 14 | May 18 |
| 28°F | Apr 7 | Apr 12 | Apr 17 | Apr 20 | Apr 23 | Apr 25 | Apr 28 | May 2 | May 7 |
| 24°F | Mar 27 | Mar 31 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 14 | Apr 18 | Apr 23 |
| 20°F | Mar 12 | Mar 17 | Mar 21 | Mar 24 | Mar 28 | Mar 30 | Apr 1 | Apr 3 | Apr 7 |
| 16°F | Mar 4 | Mar 8 | Mar 11 | Mar 14 | Mar 16 | Mar 19 | Mar 22 | Mar 27 | Mar 31 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 16 | Sep 21 | Sep 24 | Sep 27 | Sep 30 | Oct 2 | Oct 4 | Oct 6 | Oct 10 |
| 32°F | Sep 27 | Oct 1 | Oct 4 | Oct 6 | Oct 8 | Oct 11 | Oct 14 | Oct 18 | Oct 24 |
| 28°F | Oct 5 | Oct 10 | Oct 14 | Oct 18 | Oct 21 | Oct 24 | Oct 28 | Nov 1 | Nov 5 |
| 24°F | Oct 18 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 18 |
| 20°F | Nov 2 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 28 | Dec 2 |
| 16°F | Nov 16 | Nov 21 | Nov 25 | Nov 29 | Dec 1 | Dec 3 | Dec 6 | Dec 10 | Dec 16 |
Freeze probabilities 1991–2020 at Greenland, 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 03842 →Compare Hampton with another place →
Weather by month in Hampton
July is the warmest month at Greenland, NH, averaging 81°F by day and 60°F at night; January is the coldest at 33°F and 16°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 65% of years.
Warmth for growing adds up to 2,385 growing degree days a year (base 50°F), more than at 61% of the 51 New Hampshire stations. 29% of them (692) have built up by the end of June, and July adds the most, 629. Precipitation totals 50.9 inches a year, most in October (5.0") and least in January (3.6"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 33 | 16 | 3.6 | 100% | 29 | 1 |
| Feb | 36 | 18 | 3.6 | 100% | 26 | 0 |
| Mar | 43 | 25 | 4.8 | 100% | 24 | 7 |
| Apr | 56 | 35 | 4.6 | 100% | 12 | 51 |
| May | 66 | 45 | 4.0 | 65% | 2 | 196 |
| Jun | 75 | 54 | 4.6 | 0% | 0 | 437 |
| Jul | 81 | 60 | 3.9 | 0% | 0 | 629 |
| Aug | 79 | 59 | 3.7 | 0% | 0 | 592 |
| Sep | 72 | 52 | 4.1 | 17% | <1 | 357 |
| Oct | 60 | 41 | 5.0 | 97% | 6 | 98 |
| Nov | 48 | 31 | 4.1 | 100% | 18 | 16 |
| Dec | 38 | 22 | 4.9 | 100% | 27 | 1 |
Monthly normals 1991–2020 at Greenland, NH (95 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, Durham 2 SSW, NH, 14 miles northwest of Hampton, has a last frost 3 days later (May 7), a first frost 4 days earlier (October 4), a season 7 days shorter.
When it snows in Hampton, New Hampshire
The first measurable snow (0.1 inch or more) in Hampton usually arrives around December 4, and the last of the season around March 27. Those are the middle dates across the winters of 1991–2020 at N Hampton, NH, 1.6 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 38 days after the last snow.
Planting calendar for 03842
| When | What to do |
|---|---|
| February 23 – March 9 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 9 – March 23 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 6 – April 20 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 4 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 16 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 24 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 8 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 03842 is 6 miles from Greenland, NH, which stands at 95 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 8 other ZIP codes share the station; its figures are presented in full for 03801 (Portsmouth). The 2023 USDA Plant Hardiness Zone Map lists ZIP 03842 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°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.