USDA Hardiness Zone 6b
Frost Dates for 01841 — Lawrence, Massachusetts
NOAA 1991–2020 normals from Lawrence, MA (50 ft), under a mile south.
Updated
In Lawrence, the last spring frost (32°F) is around April 13 in half of years and has passed by April 29 in nine years out of ten. The first fall frost comes around October 28, as early as October 13 one year in ten, leaving a typical freeze-free season of 198 days (NOAA, Lawrence, MA).
- Last spring frost
- April 13
- First fall frost
- October 28
- Growing season
- 198 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 6
- Last snow
- March 24
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
27 of 27 observed
NOAA normal
Frost risk by date in Lawrence
Half of springs at Lawrence, MA see their last 32°F night by April 13; only one in ten is past it by April 1, and one in ten still has one after April 29. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 23 20%, and after April 29 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 87% of the 71 Massachusetts stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 28 in half of years, as early as October 13 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 12 days later, around November 9; in spring the one-in-ten date for 28°F is April 17, 12 days before the 32°F one. The freeze-free season lasts 198 days in a typical year, longer than at 86% of the 71 Massachusetts stations; it reaches 218 days one year in ten and falls short of 176 one year in ten. On average 124 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 April 25, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 12 and March 6.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 12 | Apr 17 | Apr 20 | Apr 23 | Apr 25 | Apr 29 | May 2 | May 4 | May 10 |
| 32°F | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 17 | Apr 19 | Apr 23 | Apr 29 |
| 28°F | Mar 18 | Mar 25 | Mar 29 | Apr 1 | Apr 3 | Apr 5 | Apr 7 | Apr 11 | Apr 17 |
| 24°F | Mar 8 | Mar 13 | Mar 16 | Mar 19 | Mar 22 | Mar 26 | Mar 30 | Apr 2 | Apr 5 |
| 20°F | Feb 28 | Mar 5 | Mar 8 | Mar 11 | Mar 13 | Mar 16 | Mar 20 | Mar 24 | Mar 30 |
| 16°F | Feb 18 | Feb 24 | Feb 28 | Mar 3 | Mar 6 | Mar 9 | Mar 12 | Mar 16 | Mar 22 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 2 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 | Oct 30 |
| 32°F | Oct 13 | Oct 18 | Oct 22 | Oct 26 | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 10 |
| 28°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 11 | Nov 15 | Nov 18 | Nov 25 |
| 24°F | Nov 6 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 25 | Nov 29 | Dec 2 | Dec 7 |
| 20°F | Nov 18 | Nov 23 | Nov 26 | Nov 30 | Dec 2 | Dec 5 | Dec 8 | Dec 12 | Dec 20 |
| 16°F | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 12 | Dec 17 | Dec 20 | Dec 25 | Jan 1 |
Freeze probabilities 1991–2020 at Lawrence, 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 01841 →Compare Lawrence with another place →
Weather by month in Lawrence
July is the warmest month at Lawrence, MA, averaging 83°F by day and 65°F at night; January is the coldest at 35°F and 20°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 90% of years.
Warmth for growing adds up to 3,006 growing degree days a year (base 50°F), more than at 89% of the 71 Massachusetts stations. 31% of them (928) have built up by the end of June, and July adds the most, 739. Precipitation totals 49.4 inches a year, most in March (4.7") and least in July (3.7"); May to September bring 39% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 35 | 20 | 4.2 | 100% | 28 | 1 |
| Feb | 37 | 21 | 3.8 | 100% | 26 | 1 |
| Mar | 45 | 30 | 4.7 | 100% | 21 | 12 |
| Apr | 57 | 40 | 4.2 | 90% | 6 | 80 |
| May | 68 | 50 | 3.8 | 8% | <1 | 285 |
| Jun | 77 | 59 | 4.1 | 0% | 0 | 548 |
| Jul | 83 | 65 | 3.7 | 0% | 0 | 739 |
| Aug | 81 | 64 | 3.7 | 0% | 0 | 700 |
| Sep | 74 | 56 | 3.9 | 1% | <1 | 459 |
| Oct | 62 | 44 | 4.7 | 59% | 3 | 149 |
| Nov | 51 | 35 | 3.9 | 100% | 14 | 29 |
| Dec | 41 | 26 | 4.7 | 100% | 25 | 3 |
Monthly normals 1991–2020 at Lawrence, MA (50 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, Lawrence Municipal Airport, MA, 2 miles east of Lawrence, has a last frost 8 days later (April 21), a first frost 7 days earlier (October 21), a season 16 days shorter.
When it snows in Lawrence, Massachusetts
The first measurable snow (0.1 inch or more) in Lawrence usually arrives around December 6, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Lawrence, MA, 0.9 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 20 days after the last snow.
Planting calendar for 01841
| When | What to do |
|---|---|
| February 2 – February 16 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 16 – March 2 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 16 – March 30 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 13 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 5 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 14 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 28 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 01841 is under a mile from Lawrence, MA, which stands at 50 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 01844 (Methuen). The 2023 USDA Plant Hardiness Zone Map lists ZIP 01841 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Massachusetts →
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.