USDA Hardiness Zone 6a
Frost Dates for 03109 — Manchester, New Hampshire
NOAA 1991–2020 normals from Massabesic Lake, NH (253 ft), 2 miles northeast.
Updated
In Manchester, the last spring frost (32°F) is around April 30 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around October 11, as early as September 30 one year in ten, leaving a typical freeze-free season of 164 days (NOAA, Massabesic Lake, NH).
- Last spring frost
- April 30
- First fall frost
- October 11
- Growing season
- 164 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 8
- Last snow
- March 25
- Winters with snow
- 100%
- Snow per year
- 52.8"
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Manchester
Half of springs at Massabesic Lake, NH see their last 32°F night by April 30; only one in ten is past it by April 19, and one in ten still has one after May 14. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 8 20%, and after May 14 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 11 in half of years, as early as September 30 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 13 days later, around October 24; in spring the one-in-ten date for 28°F is May 2, 12 days before the 32°F one. The freeze-free season lasts 164 days in a typical year, longer than at 88% of the 51 New Hampshire stations; it reaches 183 days one year in ten and falls short of 146 one year in ten. On average 161 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 12, and return around October 2. Severe cold of 16°F or below comes every winter, usually between December 1 and March 19.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 30 | May 3 | May 6 | May 9 | May 12 | May 15 | May 17 | May 20 | May 24 |
| 32°F | Apr 19 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 2 | May 4 | May 8 | May 14 |
| 28°F | Apr 6 | Apr 9 | Apr 11 | Apr 14 | Apr 17 | Apr 20 | Apr 23 | Apr 27 | May 2 |
| 24°F | Mar 25 | Mar 30 | Apr 1 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 13 | Apr 18 |
| 20°F | Mar 13 | Mar 18 | Mar 21 | Mar 25 | Mar 28 | Mar 31 | Apr 1 | Apr 4 | Apr 7 |
| 16°F | Mar 6 | Mar 10 | Mar 14 | Mar 16 | Mar 19 | Mar 22 | Mar 26 | Mar 29 | Apr 1 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 25 | Sep 27 | Sep 30 | Oct 2 | Oct 4 | Oct 6 | Oct 9 | Oct 14 |
| 32°F | Sep 30 | Oct 3 | Oct 6 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 22 | Oct 27 |
| 28°F | Oct 8 | Oct 13 | Oct 17 | Oct 20 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
| 24°F | Oct 20 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 22 |
| 20°F | Nov 3 | Nov 9 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 26 | Nov 29 | Dec 3 |
| 16°F | Nov 18 | Nov 22 | Nov 26 | Nov 29 | Dec 1 | Dec 3 | Dec 6 | Dec 10 | Dec 15 |
Freeze probabilities 1991–2020 at Massabesic Lake, 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 03109 →Compare Manchester with another place →
Weather by month in Manchester
July is the warmest month at Massabesic Lake, NH, averaging 81°F by day and 61°F at night; January is the coldest at 32°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 47% of years.
Warmth for growing adds up to 2,496 growing degree days a year (base 50°F), more than at 80% of the 51 New Hampshire stations. 31% of them (761) have built up by the end of June, and July adds the most, 651. Precipitation totals 42.8 inches a year, most in October (4.4") and least in January (2.7"); May to September bring 44% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 32 | 13 | 2.7 | 100% | 30 | 0 |
| Feb | 35 | 15 | 2.7 | 100% | 28 | 0 |
| Mar | 43 | 24 | 3.2 | 100% | 27 | 7 |
| Apr | 56 | 35 | 3.5 | 100% | 15 | 54 |
| May | 67 | 46 | 3.4 | 47% | 2 | 226 |
| Jun | 76 | 56 | 4.3 | 0% | 0 | 475 |
| Jul | 81 | 61 | 3.7 | 0% | 0 | 651 |
| Aug | 80 | 59 | 3.7 | 0% | 0 | 603 |
| Sep | 73 | 52 | 3.9 | 11% | 1 | 375 |
| Oct | 60 | 40 | 4.4 | 94% | 9 | 92 |
| Nov | 48 | 30 | 3.5 | 100% | 21 | 13 |
| Dec | 38 | 21 | 3.8 | 100% | 29 | 0 |
Monthly normals 1991–2020 at Massabesic Lake, NH (253 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, Manchester Airport, NH, 3 miles southwest of Manchester, has a last frost 9 days earlier (April 21), a first frost 8 days later (October 19), a season 16 days longer.
When it snows in Manchester, New Hampshire
The first measurable snow (0.1 inch or more) in Manchester usually arrives around December 8, and the last of the season around March 25. Those are the middle dates across the winters of 1991–2020 at Massabesic Lake, NH, 1.5 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 03109
| When | What to do |
|---|---|
| February 19 – March 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 5 – March 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 2 – April 16 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 30 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 19 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 11 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 03109 is 2 miles from Massabesic Lake, NH, which stands at 253 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 03104 (Manchester). The 2023 USDA Plant Hardiness Zone Map lists ZIP 03109 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.