USDA Hardiness Zone 5b
Frost Dates for 03216 — Andover, New Hampshire
NOAA 1991–2020 normals from Salisbury, NH (550 ft), 7 miles south.
Updated
In Andover, the last spring frost (32°F) is around May 14 in half of years and has passed by May 28 in nine years out of ten. The first fall frost comes around September 29, as early as September 14 one year in ten, leaving a typical freeze-free season of 138 days (NOAA, Salisbury, NH).
- Last spring frost
- May 14
- First fall frost
- September 29
- Growing season
- 138 days
- Hardiness zone
- 5b
50% probability
50% probability
freeze-free, 50%
-15 to -10°F (-26.1 to -23.3°C) coldest night
- First snow
- November 26
- Last snow
- April 8
- Winters with snow
- 100%
- Snow per year
- 68"
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in Andover
Half of springs at Salisbury, NH see their last 32°F night by May 14; only one in ten is past it by April 30, and one in ten still has one after May 28. Planting tender crops after May 20 leaves a 30% risk of a frost on them, after May 23 20%, and after May 28 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 September 29 in half of years, as early as September 14 one year in ten, and holds off past October 13 one year in ten. A hard freeze of 28°F follows 10 days later, around October 9; in spring the one-in-ten date for 28°F is May 16, 12 days before the 32°F one. The freeze-free season lasts 138 days in a typical year, shorter than at 71% of the 51 New Hampshire stations; it reaches 157 days one year in ten and falls short of 117 one year in ten. On average 171 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 13 days longer, to about May 27, and return around September 20. Severe cold of 16°F or below comes every winter, usually between November 27 and March 25.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 12 | May 17 | May 20 | May 24 | May 27 | May 29 | Jun 1 | Jun 3 | Jun 6 |
| 32°F | Apr 30 | May 4 | May 7 | May 10 | May 14 | May 17 | May 20 | May 23 | May 28 |
| 28°F | Apr 18 | Apr 23 | Apr 26 | Apr 28 | Apr 30 | May 3 | May 6 | May 10 | May 16 |
| 24°F | Apr 3 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 21 | Apr 25 | Apr 30 |
| 20°F | Mar 20 | Mar 27 | Mar 31 | Apr 2 | Apr 4 | Apr 6 | Apr 8 | Apr 11 | Apr 17 |
| 16°F | Mar 10 | Mar 14 | Mar 18 | Mar 21 | Mar 25 | Mar 29 | Mar 31 | Apr 2 | Apr 6 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 6 | Sep 11 | Sep 14 | Sep 17 | Sep 20 | Sep 23 | Sep 25 | Sep 30 | Oct 3 |
| 32°F | Sep 14 | Sep 21 | Sep 23 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 13 |
| 28°F | Sep 26 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 13 | Oct 19 | Oct 25 | Nov 1 |
| 24°F | Oct 6 | Oct 12 | Oct 17 | Oct 22 | Oct 27 | Oct 31 | Nov 4 | Nov 8 | Nov 15 |
| 20°F | Oct 22 | Oct 30 | Nov 3 | Nov 8 | Nov 13 | Nov 16 | Nov 20 | Nov 25 | Nov 30 |
| 16°F | Nov 9 | Nov 16 | Nov 19 | Nov 24 | Nov 27 | Nov 30 | Dec 2 | Dec 6 | Dec 12 |
Freeze probabilities 1991–2020 at Salisbury, 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 03216 →Compare Andover with another place →
Weather by month in Andover
July is the warmest month at Salisbury, NH, averaging 80°F by day and 57°F at night; January is the coldest at 31°F and 13°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 87% of years.
Warmth for growing adds up to 2,024 growing degree days a year (base 50°F), fewer than at 75% of the 51 New Hampshire stations. 29% of them (595) have built up by the end of June, and July adds the most, 570. Precipitation totals 48.6 inches a year, most in October (5.1") and least in February (3.2"); May to September bring 43% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 31 | 13 | 3.3 | 100% | 31 | 0 |
| Feb | 34 | 15 | 3.2 | 100% | 27 | 0 |
| Mar | 42 | 22 | 3.5 | 100% | 29 | 2 |
| Apr | 55 | 31 | 4.0 | 100% | 17 | 32 |
| May | 67 | 41 | 4.1 | 87% | 3 | 168 |
| Jun | 75 | 51 | 4.5 | 6% | 0 | 393 |
| Jul | 80 | 57 | 4.1 | 0% | 0 | 570 |
| Aug | 79 | 55 | 4.4 | 0% | 0 | 514 |
| Sep | 71 | 46 | 3.9 | 52% | 1 | 276 |
| Oct | 58 | 36 | 5.1 | 98% | 13 | 58 |
| Nov | 47 | 29 | 4.1 | 100% | 22 | 11 |
| Dec | 36 | 20 | 4.4 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Salisbury, NH (550 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, Franklin Falls Dam, NH, 7 miles east of Andover, has a last frost 7 days earlier (May 7), a first frost 4 days later (October 3), a season 10 days longer.
When it snows in Andover, New Hampshire
The first measurable snow (0.1 inch or more) in Andover usually arrives around November 26, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Bradford 2, NH, 16.9 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 36 days after the last snow.
Planting calendar for 03216
| When | What to do |
|---|---|
| March 5 – March 19 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 19 – April 2 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 16 – April 30 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 14 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 7 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 15 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 29 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 03216 is 7 miles from Salisbury, NH, which stands at 550 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 03303 (Boscawen). The 2023 USDA Plant Hardiness Zone Map lists ZIP 03216 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°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.