USDA Hardiness Zone 6a
Frost Dates for 03458 — Peterborough, New Hampshire
NOAA 1991–2020 normals from Jaffrey Silver Rch Airpark, NH (1,030 ft), 6 miles southwest.
Updated
In Peterborough, the last spring frost (32°F) is around May 5 in half of years and has passed by May 19 in nine years out of ten. The first fall frost comes around October 6, as early as September 25 one year in ten, leaving a typical freeze-free season of 154 days (NOAA, Jaffrey Silver Rch Airpark, NH).
- Last spring frost
- May 5
- First fall frost
- October 6
- Growing season
- 154 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
- November 24
- Last snow
- April 2
- Winters with snow
- 100%
- Snow per year
- 75.4"
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Peterborough
Half of springs at Jaffrey Silver Rch Airpark, NH see their last 32°F night by May 5; only one in ten is past it by April 22, and one in ten still has one after May 19. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 14 20%, and after May 19 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 6 in half of years, as early as September 25 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 13 days later, around October 19; in spring the one-in-ten date for 28°F is May 6, 13 days before the 32°F one. The freeze-free season lasts 154 days in a typical year, longer than at 63% of the 51 New Hampshire stations; it reaches 175 days one year in ten and falls short of 135 one year in ten. On average 150 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 17, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 27 and March 22.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 3 | May 7 | May 10 | May 13 | May 17 | May 20 | May 23 | May 26 | May 31 |
| 32°F | Apr 22 | Apr 27 | Apr 30 | May 2 | May 5 | May 7 | May 10 | May 14 | May 19 |
| 28°F | Apr 7 | Apr 13 | Apr 16 | Apr 19 | Apr 21 | Apr 24 | Apr 28 | May 2 | May 6 |
| 24°F | Mar 29 | Apr 1 | Apr 3 | Apr 5 | Apr 8 | Apr 10 | Apr 13 | Apr 16 | Apr 20 |
| 20°F | Mar 16 | Mar 22 | Mar 27 | Mar 30 | Apr 1 | Apr 2 | Apr 4 | Apr 6 | Apr 10 |
| 16°F | Mar 9 | Mar 13 | Mar 16 | Mar 19 | Mar 22 | Mar 25 | Mar 28 | Mar 31 | Apr 3 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 9 |
| 32°F | Sep 25 | Sep 30 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 17 | Oct 22 |
| 28°F | Oct 3 | Oct 8 | Oct 12 | Oct 16 | Oct 19 | Oct 23 | Oct 27 | Nov 1 | Nov 5 |
| 24°F | Oct 15 | Oct 21 | Oct 26 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 17 |
| 20°F | Oct 28 | Nov 3 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 21 | Nov 26 | Dec 1 |
| 16°F | Nov 11 | Nov 17 | Nov 21 | Nov 24 | Nov 27 | Nov 30 | Dec 2 | Dec 7 | Dec 13 |
Freeze probabilities 1991–2020 at Jaffrey Silver Rch Airpark, 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 03458 →Compare Peterborough with another place →
Compared with the next station
The nearest other station, Jaffrey Municipal Airport, NH, 6 miles southwest of Peterborough, has the same 50% last-frost date, the same first-frost date, a season 2 days shorter.
When it snows in Peterborough, New Hampshire
The first measurable snow (0.1 inch or more) in Peterborough usually arrives around November 24, and the last of the season around April 2. Those are the middle dates across the winters of 1991–2020 at Greenville 1 NNE, NH, 10.5 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 33 days after the last snow.
Planting calendar for 03458
| When | What to do |
|---|---|
| February 24 – March 10 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 10 – March 24 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 7 – April 21 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 5 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 14 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 22 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 6 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 03458 is 6 miles from Jaffrey Silver Rch Airpark, NH, which stands at 1,030 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 03458 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.