Fall in zone 5bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 03224 (Merrimack County, NH)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Salisbury, NH (10 miles away).
- Average last spring frostMay 1450% chance of a 32°F freeze after this date
- Average first fall frostSep 2950% chance of a 32°F freeze by this date
- Growing season (frost-free)138 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 to -10°F avg. coldest night
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Frost and freeze alerts from the NWS forecast for 03224, the spring soil-temperature heads-up for pre-emergent, and a short weekly yard-timing email.
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
50°F 50–55°F
24-hour average · latest 47°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Durham 2 N (33 mi), Durham 2 SSW (34 mi), Hubbard Brook (42 mi).
4-inch depth
52°F 50–55°F
24-hour average · latest 50°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Durham 2 N (33 mi), Durham 2 SSW (34 mi), Hubbard Brook (42 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 03224 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 52°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent window is mostly past. Next: spring, when soil reaches 50°F (typically mid-April to early May).
Fertilizer window
Lawn region: North (cool-season). Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Apr 30 |
| 50% (the "average" last frost) | May 14 |
| 10% (cautious: only 1 year in 10 freezes later) | May 28 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Sep 14 |
| 50% (the "average" first frost) | Sep 29 |
| 90% (late: most years have frozen by now) | Oct 13 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 27 | Sep 20 |
| 32°F (freeze) | May 14 | Sep 29 |
| 28°F (hard freeze) | Apr 30 | Oct 9 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 03224
Dates count from your average last spring frost (May 14) and first fall frost (Sep 29). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Mar 19–Apr 2 | May 21–Jun 4 (transplant) | – |
| Pepper (sweet and hot) | Mar 5–19 | May 28–Jun 11 (transplant) | – |
| Eggplant | Mar 5–19 | May 28–Jun 11 (transplant) | – |
| Tomatillo | Mar 19–Apr 2 | May 21–Jun 4 (transplant) | – |
| Lettuce | Mar 19–Apr 2 | Apr 23–May 14 (transplant) Apr 16–May 28 (sow outdoors) | Aug 4–25 (transplant) Jul 21–Aug 18 (sowing) |
| Spinach | – | Apr 2–23 (sow outdoors) | Aug 4–25 (sowing) |
| Kale | Mar 19–Apr 2 | Apr 16–30 (transplant) Apr 16–30 (sow outdoors) | Jul 7–Aug 4 (transplant) Jun 23–Jul 21 (sowing) |
| Collards | Mar 19–Apr 2 | Apr 16–May 14 (transplant) Apr 16–May 14 (sow outdoors) | Jul 7–Aug 4 (transplant) Jun 23–Jul 21 (sowing) |
| Broccoli | Mar 5–19 | Apr 16–30 (transplant) | Jun 23–Jul 21 (transplant) |
| Cabbage | Mar 5–19 | Apr 16–30 (transplant) | Jun 23–Jul 21 (transplant) |
| Cauliflower | Mar 5–19 | Apr 30–May 14 (transplant) | Jun 23–Jul 21 (transplant) |
| Brussels sprouts | Feb 19–Mar 5 | Apr 16–30 (transplant) | Jun 9–30 (transplant) |
| Kohlrabi | Mar 19–Apr 2 | Apr 16–30 (transplant) Apr 16–30 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Bok choy / Asian greens | – | Apr 16–30 (sow outdoors) | Aug 4–18 (sowing) |
| Arugula | – | Apr 16–May 14 (sow outdoors) | Aug 4–Sep 1 (sowing) |
| Mustard greens | – | Apr 16–May 7 (sow outdoors) | Aug 4–18 (sowing) |
| Swiss chard | Apr 2–16 | Apr 30–May 21 (transplant) Apr 30–May 28 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Beet | – | Apr 16–May 14 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Carrot | – | Apr 23–May 21 (sow outdoors) | Jul 7–21 (sowing) |
| Radish | – | Apr 9–May 21 (sow outdoors) | Aug 18–Sep 1 (sowing) |
| Turnip | – | Apr 16–May 7 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Parsnip | – | Apr 23–May 14 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 19–Apr 16 (sow outdoors) | Jul 7–21 (sowing) |
| Onion (bulbing) | Feb 19–Mar 5 | Apr 2–16 (transplant) | – |
| Green onion / scallion | – | Apr 2–30 (sow outdoors) | Jul 21–Aug 4 (sowing) |
| Leek | Feb 19–Mar 5 | Apr 16–30 (transplant) | – |
| Garlic | – | – | Aug 18–Sep 15 (sowing) |
| Shallot | – | Apr 2–16 (transplant) | Aug 18–Sep 15 (sowing) |
| Potato | – | Apr 16–30 (transplant) | Jun 9–23 (transplant) |
| Sweet potato | – | Jun 4–18 (transplant) | – |
| Sweet corn | – | May 21–Jun 4 (sow outdoors) | – |
| Bean, bush (snap) | – | May 21–Jun 4 (sow outdoors) | – |
| Bean, pole | – | May 21–Jun 4 (sow outdoors) | – |
| Lima bean | – | May 28–Jun 11 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 4–25 (sow outdoors) | – |
| Cucumber | Apr 16–23 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Summer squash / zucchini | Apr 16–23 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Winter squash | Apr 16–23 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Pumpkin | – | May 21–Jun 4 (sow outdoors) | – |
| Watermelon | Apr 16–23 | May 28–Jun 11 (transplant) May 28–Jun 11 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 16–23 | May 28–Jun 11 (transplant) May 28–Jun 11 (sow outdoors) | – |
| Okra | Apr 2–16 | May 28–Jun 11 (transplant) May 28–Jun 11 (sow outdoors) | – |
| Celery | Feb 19–Mar 5 | May 21–28 (transplant) | – |
| Basil | Apr 2–16 | May 21–Jun 4 (transplant) May 21–Jun 4 (sow outdoors) | – |
| Cilantro | – | Apr 30–May 28 (sow outdoors) | Aug 4–18 (sowing) |
| Parsley | Mar 5–19 | Apr 30–May 14 (transplant) Apr 23–May 14 (sow outdoors) | – |
| Dill | – | May 14–28 (sow outdoors) | Aug 4–18 (sowing) |
| Sunflower | – | May 14–28 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 16–30 (transplant) | – |
| Rhubarb (crowns) | – | Apr 16–30 (transplant) | – |
| Strawberry (plants) | – | Apr 16–30 (transplant) | Jul 21–Aug 18 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Salisbury, NH (NOAA GHCN-Daily ID USC00277833), elevation 550 ft, 9.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Franklin Falls Dam, NH | 10 mi | May 7 | Oct 3 |
| Concord Muni AP, NH | 11 mi | May 8 | Oct 3 |
| Lakeport 2, NH | 14 mi | Apr 30 | Oct 18 |
The average last-frost dates of these stations span 15 days, a rough guide to local variation. See data sources & methods.
Frost questions for 03224
When is the last frost in 03224?
The average (50% chance) last spring freeze of 32°F for ZIP 03224 is May 14. For a more cautious planting date, use May 28, when only 1 year in 10 still sees a later freeze.
When is the first frost in 03224?
The average first fall freeze is September 29. In 1 year in 10 it comes by September 14.
What hardiness zone is 03224?
ZIP 03224 is in USDA zone 5b (-15 to -10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 03224 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
03307 Loudon 03276 Tilton Northfield 03303 Concord 03301 Concord 03258 03220 Belmont 03235 Franklin 03237
Other ZIP codes in Merrimack County
03046 03106 03216 03221 03229 03230 03231 03233 03234 03235 03242 03243 03255 03257 03258 03260 03263 03268 03273 03275 03276 03278 03287 03301 All Merrimack County frost dates · New Hampshire frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.