USDA Hardiness Zone 6a
Frost Dates for 03858 — Newton, New Hampshire
NOAA 1991–2020 normals from Haverhill, MA (20 ft), 8 miles south.
Updated
In Newton, the last spring frost (32°F) is around May 1 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around October 12, as early as October 1 one year in ten, leaving a typical freeze-free season of 163 days (NOAA, Haverhill, MA).
- Last spring frost
- May 1
- First fall frost
- October 12
- Growing season
- 163 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 3
- Last snow
- March 29
- Winters with snow
- 100%
- Snow per year
- 57.8"
median, 1991–2020
median, 1991–2020
27 of 27 observed
NOAA normal
Frost risk by date in Newton
Half of springs at Haverhill, MA see their last 32°F night by May 1; only one in ten is past it by April 20, and one in ten still has one after May 14. Planting tender crops after May 5 leaves a 30% risk of a frost on them, after May 9 20%, and after May 14 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 67% of the 51 New Hampshire stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 12 in half of years, as early as October 1 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 11 days later, around October 23; in spring the one-in-ten date for 28°F is May 1, 13 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, longer than at 86% of the 51 New Hampshire stations; it reaches 183 days one year in ten and falls short of 144 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 11 days longer, to about May 12, and return around October 3. Severe cold of 16°F or below comes every winter, usually between December 2 and March 15.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 30 | May 4 | May 7 | May 9 | May 12 | May 15 | May 18 | May 20 | May 23 |
| 32°F | Apr 20 | Apr 24 | Apr 27 | Apr 29 | May 1 | May 3 | May 5 | May 9 | May 14 |
| 28°F | Apr 6 | Apr 9 | Apr 12 | Apr 16 | Apr 19 | Apr 21 | Apr 24 | Apr 26 | May 1 |
| 24°F | Mar 24 | Mar 30 | Apr 1 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 14 | Apr 19 |
| 20°F | Mar 10 | Mar 15 | Mar 19 | Mar 24 | Mar 27 | Mar 30 | Mar 31 | Apr 2 | Apr 6 |
| 16°F | Mar 1 | Mar 7 | Mar 10 | Mar 13 | Mar 15 | Mar 19 | Mar 22 | Mar 26 | Mar 30 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 21 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 5 | Oct 7 | Oct 11 | Oct 15 |
| 32°F | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 19 | Oct 23 | Oct 28 |
| 28°F | Oct 7 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 2 | Nov 7 |
| 24°F | Oct 18 | Oct 24 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 14 | Nov 20 |
| 20°F | Nov 2 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 26 | Nov 30 | Dec 5 |
| 16°F | Nov 18 | Nov 23 | Nov 27 | Nov 30 | Dec 2 | Dec 5 | Dec 8 | Dec 12 | Dec 20 |
Freeze probabilities 1991–2020 at Haverhill, MA, 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 03858 →Compare Newton with another place →
Weather by month in Newton
July is the warmest month at Haverhill, MA, averaging 82°F by day and 61°F at night; January is the coldest at 35°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 September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 52% of years.
Warmth for growing adds up to 2,524 growing degree days a year (base 50°F), more than at 84% of the 51 New Hampshire stations. 29% of them (732) have built up by the end of June, and July adds the most, 674. Precipitation totals 49.6 inches a year, most in October (5.3") and least in January (3.5"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 35 | 16 | 3.5 | 100% | 29 | 1 |
| Feb | 38 | 17 | 3.6 | 100% | 26 | 0 |
| Mar | 45 | 24 | 4.8 | 100% | 24 | 8 |
| Apr | 57 | 34 | 4.3 | 100% | 12 | 49 |
| May | 68 | 45 | 4.1 | 52% | 1 | 212 |
| Jun | 76 | 54 | 4.2 | 0% | 0 | 463 |
| Jul | 82 | 61 | 3.6 | 0% | 0 | 674 |
| Aug | 81 | 59 | 3.8 | 0% | 0 | 618 |
| Sep | 74 | 51 | 4.0 | 7% | <1 | 372 |
| Oct | 62 | 40 | 5.3 | 94% | 6 | 106 |
| Nov | 51 | 31 | 3.9 | 100% | 18 | 20 |
| Dec | 40 | 22 | 4.5 | 100% | 27 | 2 |
Monthly normals 1991–2020 at Haverhill, MA (20 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, W Hampstead, NH, 8 miles west of Newton and 268 feet higher, has a last frost 1 day earlier (April 30), a first frost 1 day earlier (October 11), a season 1 day shorter.
When it snows in Newton, New Hampshire
The first measurable snow (0.1 inch or more) in Newton usually arrives around December 3, and the last of the season around March 29. Those are the middle dates across the winters of 1991–2020 at Haverhill, MA, 7.8 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 33 days after the last snow.
Planting calendar for 03858
| When | What to do |
|---|---|
| February 20 – March 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 6 – March 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 3 – April 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 1 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 20 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 28 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 12 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 03858 is 8 miles from Haverhill, MA, which stands at 20 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 01830 (Haverhill). The 2023 USDA Plant Hardiness Zone Map lists ZIP 03858 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.