Frost dates for 07430Mahwah, NJ
The average last spring frost in Mahwah is April 19 and the average first fall frost is October 23, giving a typical growing season of about 188 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 19
- Average first fall frost
- Oct 23
- Growing season
- 188 days
Safer after May 3 (1-in-10 risk)
Possible by Oct 9 (1-in-10 risk)
Last frost typically in 167 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 18 · Apr 30 · May 16 | Oct 3 · Oct 13 · Oct 27 | 164 days | 100% |
| Frost / freeze (32°F) | Apr 5 · Apr 19 · May 3 | Oct 9 · Oct 23 · Nov 6 | 188 days | 100% |
| Hard freeze (28°F) | Mar 21 · Apr 4 · Apr 19 | Oct 16 · Nov 4 · Nov 21 | 213 days | 100% |
Planting calendar for Mahwah
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 19 – May 25 |
| Tomatoes | Transplant outdoors | May 5 – Jul 3 |
| Peppers | Start seeds indoors | Mar 19 – Apr 19 |
| Peppers | Transplant outdoors | May 19 – Jun 19 |
| Eggplant | Start seeds indoors | Apr 5 – May 4 |
| Eggplant | Transplant outdoors | May 19 – Jun 19 |
| Cucumbers | Sow outdoors | May 19 – Jul 13 |
| Summer squash | Sow outdoors | May 5 – Jun 19 |
| Winter squash & pumpkins | Sow outdoors | May 19 – Jun 19 |
| Snap beans | Sow outdoors | May 5 – Aug 5 |
| Sweet corn | Sow outdoors | May 5 – Jul 3 |
| Watermelon & cantaloupe | Sow outdoors | May 19 – Jun 19 |
| Okra | Sow outdoors | May 12 – Jun 4 |
| Peas | Sow outdoors (spring) | Mar 19 – May 4 |
| Potatoes | Plant outdoors (spring) | Mar 19 – May 19 |
| Onions | Start seeds indoors (spring) | Feb 5 – Mar 4 |
| Onions | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (spring) | Mar 1 – Apr 4 |
| Broccoli | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (fall) | Jun 23 – Jul 3 |
| Broccoli | Transplant outdoors (fall) | Jul 23 – Aug 3 |
| Cabbage | Start seeds indoors (spring) | Feb 19 – Mar 19 |
| Cabbage | Transplant outdoors (spring) | Mar 19 – Apr 19 |
| Cabbage | Start seeds indoors (fall) | Jun 13 – Jul 13 |
| Cabbage | Transplant outdoors (fall) | Jul 13 – Aug 13 |
| Leaf lettuce | Sow outdoors (spring) | Mar 19 – Jun 4 |
| Leaf lettuce | Sow outdoors (fall) | Jul 13 – Aug 29 |
| Spinach | Sow outdoors (spring) | Mar 12 – Apr 25 |
| Spinach | Sow outdoors (fall) | Jul 30 – Sep 3 |
| Radishes | Sow outdoors (spring) | Mar 19 – May 9 |
| Radishes | Sow outdoors (fall) | Jul 13 – Sep 13 |
| Kale | Sow outdoors (spring) | Apr 5 – Apr 25 |
| Kale | Sow outdoors (fall) | Jul 6 – Aug 13 |
| Carrots | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Carrots | Sow outdoors (fall) | Jun 13 – Jul 29 |
| Garlic | Plant outdoors (fall) | Oct 13 – Nov 13 |
Where these dates come from
ZIP code 07430 is matched to the NOAA station Wanaque Raymond Dam, NJ, 9.9 km away, at 245 ft elevation (2 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Wanaque Raymond Dam, NJ (used) | 245 ft | Apr 19 | Oct 23 |
| Charlotteburg Rsvr, NJ | 778 ft | Apr 25 | Oct 17 |
| Little Falls, NJ | 150 ft | Apr 15 | Oct 28 |
| Caldwell Essex Co Ap, NJ | 173 ft | Apr 14 | Oct 28 |
Frost dates near Mahwah
- Mahwah, NJ 07495 · last Apr 19, first Oct 23
- Ramsey, NJ 07446 · last Apr 18, first Oct 24
- Hillburn, NY 10931 · last Apr 19, first Oct 23
- Suffern, NY 10901 · last Apr 20, first Oct 26
- Ringwood, NJ 07456 · last Apr 19, first Oct 23
- Allendale, NJ 07401 · last Apr 14, first Oct 28
- Oakland, NJ 07436 · last Apr 18, first Oct 24
- Tallman, NY 10982 · last Apr 20, first Oct 26
Frequently asked questions
- When is the last frost in Mahwah, NJ?
- For ZIP code 07430, the average last spring frost (32°F) is April 19, based on NOAA 1991-2020 climate normals for the Wanaque Raymond Dam, NJ weather station. There is a 1-in-10 chance of a frost after May 3.
- When is the first frost in Mahwah, NJ?
- The average first fall frost (32°F) is October 23. There is a 1-in-10 chance of frost by October 9, so tender plants are at risk from that point on.
- How long is the growing season in 07430?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 188 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.