Frost dates for 08690Trenton, NJ
The average last spring frost in Trenton is April 25 and the average first fall frost is October 16, giving a typical growing season of about 173 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 25
- Average first fall frost
- Oct 16
- Growing season
- 173 days
Safer after May 12 (1-in-10 risk)
Possible by Oct 4 (1-in-10 risk)
Last frost typically in 173 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 24 · May 8 · May 23 | Sep 26 · Oct 6 · Oct 19 | 151 days | 100% |
| Frost / freeze (32°F) | Apr 12 · Apr 25 · May 12 | Oct 4 · Oct 16 · Oct 29 | 173 days | 100% |
| Hard freeze (28°F) | Mar 26 · Apr 10 · Apr 26 | Oct 13 · Oct 28 · Nov 11 | 200 days | 100% |
Planting calendar for Trenton
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 25 – May 31 |
| Tomatoes | Transplant outdoors | May 11 – Jun 26 |
| Peppers | Start seeds indoors | Mar 25 – Apr 25 |
| Peppers | Transplant outdoors | May 25 – Jun 25 |
| Eggplant | Start seeds indoors | Apr 11 – May 10 |
| Eggplant | Transplant outdoors | May 25 – Jun 25 |
| Cucumbers | Sow outdoors | May 25 – Jul 6 |
| Summer squash | Sow outdoors | May 11 – Jun 25 |
| Winter squash & pumpkins | Sow outdoors | May 25 – Jun 25 |
| Snap beans | Sow outdoors | May 11 – Jul 29 |
| Sweet corn | Sow outdoors | May 11 – Jun 26 |
| Watermelon & cantaloupe | Sow outdoors | May 25 – Jun 25 |
| Okra | Sow outdoors | May 18 – Jun 10 |
| Peas | Sow outdoors (spring) | Mar 25 – May 10 |
| Potatoes | Plant outdoors (spring) | Mar 25 – May 25 |
| Onions | Start seeds indoors (spring) | Feb 11 – Mar 10 |
| Onions | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (spring) | Mar 7 – Apr 10 |
| Broccoli | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (fall) | Jun 16 – Jun 26 |
| Broccoli | Transplant outdoors (fall) | Jul 16 – Jul 27 |
| Cabbage | Start seeds indoors (spring) | Feb 25 – Mar 25 |
| Cabbage | Transplant outdoors (spring) | Mar 25 – Apr 25 |
| Cabbage | Start seeds indoors (fall) | Jun 6 – Jul 6 |
| Cabbage | Transplant outdoors (fall) | Jul 6 – Aug 6 |
| Leaf lettuce | Sow outdoors (spring) | Mar 25 – Jun 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 6 – Aug 22 |
| Spinach | Sow outdoors (spring) | Mar 18 – May 1 |
| Spinach | Sow outdoors (fall) | Jul 23 – Aug 27 |
| Radishes | Sow outdoors (spring) | Mar 25 – May 15 |
| Radishes | Sow outdoors (fall) | Jul 6 – Sep 6 |
| Kale | Sow outdoors (spring) | Apr 11 – May 1 |
| Kale | Sow outdoors (fall) | Jun 29 – Aug 6 |
| Carrots | Sow outdoors (spring) | Apr 25 – Jun 10 |
| Carrots | Sow outdoors (fall) | Jun 6 – Jul 22 |
| Garlic | Plant outdoors (fall) | Oct 6 – Nov 6 |
Where these dates come from
ZIP code 08690 is matched to the NOAA station Hightstown 2 W, NJ, 8.7 km away, at 100 ft elevation (5 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hightstown 2 W, NJ (used) | 100 ft | Apr 25 | Oct 16 |
| Trenton State College, NJ | 100 ft | Apr 17 | Oct 28 |
| Trenton Mercer Co Ap, NJ | 184 ft | Apr 10 | Nov 1 |
| Wertsville 4 Ne, NJ | 283 ft | Apr 16 | Oct 27 |
Frost dates near Trenton
- Trenton, NJ 08619 · last Apr 25, first Oct 16
- Princeton Junction, NJ 08550 · last Apr 25, first Oct 16
- Millstone Township, NJ 08535 · last Apr 10, first Nov 1
- Windsor, NJ 08561 · last Apr 25, first Oct 16
- Princeton, NJ 08543 · last Apr 25, first Oct 16
- Joint Base Mdl, NJ 08640 · last Apr 10, first Nov 1
- Lawrence Township, NJ 08648 · last Apr 10, first Nov 1
- Allentown, NJ 08501 · last Apr 25, first Oct 16
Frequently asked questions
- When is the last frost in Trenton, NJ?
- For ZIP code 08690, the average last spring frost (32°F) is April 25, based on NOAA 1991-2020 climate normals for the Hightstown 2 W, NJ weather station. There is a 1-in-10 chance of a frost after May 12.
- When is the first frost in Trenton, NJ?
- The average first fall frost (32°F) is October 16. There is a 1-in-10 chance of frost by October 4, so tender plants are at risk from that point on.
- How long is the growing season in 08690?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 173 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.