USDA Hardiness Zone 5b
Frost Dates for 03221 — Bradford, New Hampshire
NOAA 1991–2020 normals from Bradford 2, NH (815 ft), 2 miles west.
Updated
In Bradford, the last spring frost (32°F) is around May 15 in half of years and has passed by May 29 in nine years out of ten. The first fall frost comes around September 27, as early as September 15 one year in ten, leaving a typical freeze-free season of 135 days (NOAA, Bradford 2, NH).
- Last spring frost
- May 15
- First fall frost
- September 27
- Growing season
- 135 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 Bradford
Half of springs at Bradford 2, NH see their last 32°F night by May 15; only one in ten is past it by April 30, and one in ten still has one after May 29. Planting tender crops after May 21 leaves a 30% risk of a frost on them, after May 25 20%, and after May 29 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 27 in half of years, as early as September 15 one year in ten, and holds off past October 9 one year in ten. A hard freeze of 28°F follows 11 days later, around October 8; in spring the one-in-ten date for 28°F is May 17, 12 days before the 32°F one. The freeze-free season lasts 135 days in a typical year, shorter than at 76% of the 51 New Hampshire stations; it reaches 155 days one year in ten and falls short of 115 one year in ten. On average 176 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 14 days longer, to about May 29, and return around September 17. Severe cold of 16°F or below comes every winter, usually between November 18 and March 29.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 14 | May 19 | May 23 | May 26 | May 29 | May 31 | Jun 3 | Jun 7 | Jun 11 |
| 32°F | Apr 30 | May 5 | May 9 | May 12 | May 15 | May 18 | May 21 | May 25 | May 29 |
| 28°F | Apr 19 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 4 | May 7 | May 12 | May 17 |
| 24°F | Apr 4 | Apr 8 | Apr 11 | Apr 15 | Apr 17 | Apr 19 | Apr 22 | Apr 26 | May 1 |
| 20°F | Mar 23 | Mar 30 | Apr 1 | Apr 3 | Apr 4 | Apr 6 | Apr 8 | Apr 12 | Apr 17 |
| 16°F | Mar 13 | Mar 18 | Mar 22 | Mar 25 | Mar 29 | Mar 31 | Apr 2 | Apr 4 | Apr 7 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 6 | Sep 10 | Sep 12 | Sep 15 | Sep 17 | Sep 20 | Sep 23 | Sep 26 | Oct 1 |
| 32°F | Sep 15 | Sep 18 | Sep 22 | Sep 24 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 9 |
| 28°F | Sep 25 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 20 | Oct 27 |
| 24°F | Oct 5 | Oct 10 | Oct 15 | Oct 19 | Oct 23 | Oct 27 | Oct 31 | Nov 4 | Nov 9 |
| 20°F | Oct 20 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 21 |
| 16°F | Nov 3 | Nov 8 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Nov 28 | Dec 3 |
Freeze probabilities 1991–2020 at Bradford 2, 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 03221 →Compare Bradford with another place →
Compared with the next station
The nearest other station, Mt Sunapee, NH, 8 miles northwest of Bradford and 460 feet higher, has a last frost 13 days earlier (May 2), a first frost 12 days later (October 9), a season 23 days longer.
When it snows in Bradford, New Hampshire
The first measurable snow (0.1 inch or more) in Bradford 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, 2.4 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 37 days after the last snow.
Planting calendar for 03221
| When | What to do |
|---|---|
| March 6 – March 20 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 20 – April 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 17 – May 1 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 15 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 5 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 13 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 27 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 03221 is 2 miles from Bradford 2, NH, which stands at 815 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 03221 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.