Planting zone for 03272 — South Newbury, NH
ZIP code 03272 (South Newbury, Merrimack County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 15 and the first fall frost September 27.
Where ZIP 03272 is
tap the map for the zone at any spot · scroll or pinch to zoomNot the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.
Was 5a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →
Frost forecast — next 7 nights
live from the National Weather ServiceLoading the forecast for South Newbury, NH…
Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.
Frost dates in South Newbury, NH
A hard freeze (28 °F) usually ends around May 1 and returns around October 8.
From the NOAA station Bradford 2, NH — 2 miles away, elevation 814 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.
When to plant vegetables in 03272
Counted from the median last spring frost (May 15) and first fall frost (Sep 27) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.
When spring arrived in 2026
In 2026, spring leaf-out near 03272 came on Apr 15 — 5 days earlier than the 1991–2020 average (Apr 20).
Apr 202026
Apr 15
The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).
Native plants for zone 5b in New Hampshire
475 plants native to the lower 48 states, recorded in New Hampshire, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.
Trees 53
Shrubs 96
Wildflowers & perennials 167
Grasses 141
Vines 6
Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in South Newbury, NH.
Soil in South Newbury, NH
The soil mapped at the center of ZIP 03272 is Adams — loamy sand, somewhat excessively drained.
Map unit: Adams-Urban land complex, 0 to 8 percent slopes.
Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 03272; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in South Newbury, NH
Average high and low, by month
Precipitation by month inches · ❄ = snowfall
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bradford 2, NH (2 mi away); precipitation: Bradford 2, NH (2 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.
Questions about 03272
What planting zone is ZIP code 03272?
ZIP code 03272 (South Newbury, NH) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).
When is the last frost in South Newbury, NH?
The median last spring frost (32 °F) near 03272 is May 15; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bradford 2 station.
When is the first frost in South Newbury, NH?
The median first fall frost near 03272 is September 27, giving a median frost-free growing season of 135 days.
When should I plant tomatoes in 03272?
Start tomato seeds indoors around Mar 20 – Apr 3 and set transplants outside around May 22 – Jun 5, one to three weeks after the median last frost.
How much rain and snow does 03272 get?
About 49.5 inches of precipitation a year and 68 inches of snowfall (NOAA 1991–2020 normals, Bradford 2 station).
How hot do summers get in South Newbury, NH?
The average high peaks at 80 °F in July, with about 3 days a year at 90 °F or more.
What kind of soil does 03272 have?
The USDA soil survey maps Adams at the center of ZIP 03272: loamy sand, somewhat excessively drained, pH about 4.8 (strongly acidic).
Did spring come early in South Newbury, NH in 2026?
Spring leaf-out near 03272 came on Apr 15 in 2026, 5 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.
What kind of onions grow in South Newbury, NH?
Long-day onions: the longest day near 03272 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).
Did the zone for 03272 change?
Yes. The 2012 USDA map put 03272 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.