Fall in zone 6bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 02478 (Belmont, MA)
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, Jamaica Plain, MA (7 miles away).
- Average last spring frostApr 1950% chance of a 32°F freeze after this date
- Average first fall frostOct 2350% chance of a 32°F freeze by this date
- Growing season (frost-free)185 daysmedian, 32°F threshold
- USDA hardiness zone6b-5 to 0°F avg. coldest night
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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
52°F 50–55°F
24-hour average · latest 48°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Durham 2 SSW (51 mi), Durham 2 N (55 mi).
4-inch depth
53°F 50–55°F
24-hour average · latest 51°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Durham 2 SSW (51 mi), Durham 2 N (55 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 02478 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 53°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.
Your average first frost is Oct 23: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
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 6 |
| 50% (the "average" last frost) | Apr 19 |
| 10% (cautious: only 1 year in 10 freezes later) | May 3 |
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) | Oct 8 |
| 50% (the "average" first frost) | Oct 23 |
| 90% (late: most years have frozen by now) | Nov 5 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 2 | Oct 10 |
| 32°F (freeze) | Apr 19 | Oct 23 |
| 28°F (hard freeze) | Apr 5 | Nov 3 |
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 02478
Dates count from your average last spring frost (Apr 19) and first fall frost (Oct 23). 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 | Feb 22–Mar 8 | Apr 26–May 10 (transplant) | – |
| Pepper (sweet and hot) | Feb 8–22 | May 3–17 (transplant) | – |
| Eggplant | Feb 8–22 | May 3–17 (transplant) | – |
| Tomatillo | Feb 22–Mar 8 | Apr 26–May 10 (transplant) | – |
| Lettuce | Feb 22–Mar 8 | Mar 29–Apr 19 (transplant) Mar 22–May 3 (sow outdoors) | Aug 28–Sep 18 (transplant) Aug 14–Sep 11 (sowing) |
| Spinach | – | Mar 8–29 (sow outdoors) | Aug 28–Sep 18 (sowing) |
| Kale | Feb 22–Mar 8 | Mar 22–Apr 5 (transplant) Mar 22–Apr 5 (sow outdoors) | Jul 31–Aug 28 (transplant) Jul 17–Aug 14 (sowing) |
| Collards | Feb 22–Mar 8 | Mar 22–Apr 19 (transplant) Mar 22–Apr 19 (sow outdoors) | Jul 31–Aug 28 (transplant) Jul 17–Aug 14 (sowing) |
| Broccoli | Feb 8–22 | Mar 22–Apr 5 (transplant) | Jul 17–Aug 14 (transplant) |
| Cabbage | Feb 8–22 | Mar 22–Apr 5 (transplant) | Jul 17–Aug 14 (transplant) |
| Cauliflower | Feb 8–22 | Apr 5–19 (transplant) | Jul 17–Aug 14 (transplant) |
| Brussels sprouts | Jan 25–Feb 8 | Mar 22–Apr 5 (transplant) | Jul 3–24 (transplant) |
| Kohlrabi | Feb 22–Mar 8 | Mar 22–Apr 5 (transplant) Mar 22–Apr 5 (sow outdoors) | Aug 14–28 (sowing) |
| Bok choy / Asian greens | – | Mar 22–Apr 5 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Arugula | – | Mar 22–Apr 19 (sow outdoors) | Aug 28–Sep 25 (sowing) |
| Mustard greens | – | Mar 22–Apr 12 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Swiss chard | Mar 8–22 | Apr 5–26 (transplant) Apr 5–May 3 (sow outdoors) | Aug 14–28 (sowing) |
| Beet | – | Mar 22–Apr 19 (sow outdoors) | Aug 14–28 (sowing) |
| Carrot | – | Mar 29–Apr 26 (sow outdoors) | Jul 31–Aug 14 (sowing) |
| Radish | – | Mar 15–Apr 26 (sow outdoors) | Sep 11–25 (sowing) |
| Turnip | – | Mar 22–Apr 12 (sow outdoors) | Aug 14–28 (sowing) |
| Parsnip | – | Mar 29–Apr 19 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Feb 22–Mar 22 (sow outdoors) | Jul 31–Aug 14 (sowing) |
| Onion (bulbing) | Jan 25–Feb 8 | Mar 8–22 (transplant) | – |
| Green onion / scallion | – | Mar 8–Apr 5 (sow outdoors) | Aug 14–28 (sowing) |
| Leek | Jan 25–Feb 8 | Mar 22–Apr 5 (transplant) | – |
| Garlic | – | – | Sep 11–Oct 9 (sowing) |
| Shallot | – | Mar 8–22 (transplant) | Sep 11–Oct 9 (sowing) |
| Potato | – | Mar 22–Apr 5 (transplant) | Jul 3–17 (transplant) |
| Sweet potato | – | May 10–24 (transplant) | – |
| Sweet corn | – | Apr 26–May 10 (sow outdoors) | – |
| Bean, bush (snap) | – | Apr 26–May 10 (sow outdoors) | – |
| Bean, pole | – | Apr 26–May 10 (sow outdoors) | – |
| Lima bean | – | May 3–17 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 10–31 (sow outdoors) | – |
| Cucumber | Mar 22–29 | Apr 26–May 10 (transplant) Apr 26–May 10 (sow outdoors) | – |
| Summer squash / zucchini | Mar 22–29 | Apr 26–May 10 (transplant) Apr 26–May 10 (sow outdoors) | – |
| Winter squash | Mar 22–29 | Apr 26–May 10 (transplant) Apr 26–May 10 (sow outdoors) | – |
| Pumpkin | – | Apr 26–May 10 (sow outdoors) | – |
| Watermelon | Mar 22–29 | May 3–17 (transplant) May 3–17 (sow outdoors) | – |
| Cantaloupe / muskmelon | Mar 22–29 | May 3–17 (transplant) May 3–17 (sow outdoors) | – |
| Okra | Mar 8–22 | May 3–17 (transplant) May 3–17 (sow outdoors) | – |
| Celery | Jan 25–Feb 8 | Apr 26–May 3 (transplant) | – |
| Basil | Mar 8–22 | Apr 26–May 10 (transplant) Apr 26–May 10 (sow outdoors) | – |
| Cilantro | – | Apr 5–May 3 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Parsley | Feb 8–22 | Apr 5–19 (transplant) Mar 29–Apr 19 (sow outdoors) | – |
| Dill | – | Apr 19–May 3 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Sunflower | – | Apr 19–May 3 (sow outdoors) | – |
| Asparagus (crowns) | – | Mar 22–Apr 5 (transplant) | – |
| Rhubarb (crowns) | – | Mar 22–Apr 5 (transplant) | – |
| Strawberry (plants) | – | Mar 22–Apr 5 (transplant) | Aug 14–Sep 11 (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: Jamaica Plain, MA (NOAA GHCN-Daily ID USC00193890), elevation 95 ft, 7.0 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Bedford Hanscom Fld, MA | 8 mi | Apr 28 | Oct 10 |
| Bedford, MA | 8 mi | Apr 27 | Oct 13 |
| Boston Logan Intl AP, MA | 9 mi | Apr 4 | Nov 9 |
The average last-frost dates of these stations span 24 days, a rough guide to local variation. See data sources & methods.
Frost questions for 02478
When is the last frost in 02478?
The average (50% chance) last spring freeze of 32°F for ZIP 02478 is April 19. For a more cautious planting date, use May 3, when only 1 year in 10 still sees a later freeze.
When is the first frost in 02478?
The average first fall freeze is October 23. In 1 year in 10 it comes by October 8.
What hardiness zone is 02478?
ZIP 02478 is in USDA zone 6b (-5 to 0°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 02478 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
02476 Arlington 02472 Watertown Town 02452 Waltham 02474 Arlington 02140 Cambridge 02138 Cambridge 02458 Newton 02144 Somerville
Other ZIP codes in Middlesex County
01431 01432 01450 01460 01463 01464 01469 01474 01701 01702 01718 01719 01720 01721 01730 01731 01741 01742 01746 01748 01749 01752 01754 01760 All Middlesex County frost dates · Massachusetts 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.