Frost dates for 07981Whippany, NJ
The average last spring frost in Whippany is April 18 and the average first fall frost is October 27, giving a typical growing season of about 189 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 18
- Average first fall frost
- Oct 27
- Growing season
- 189 days
Safer after May 6 (1-in-10 risk)
Possible by Oct 11 (1-in-10 risk)
Last frost typically in 166 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 17 · Apr 30 · May 17 | Oct 2 · Oct 15 · Oct 31 | 166 days | 100% |
| Frost / freeze (32°F) | Apr 3 · Apr 18 · May 6 | Oct 11 · Oct 27 · Nov 10 | 189 days | 100% |
| Hard freeze (28°F) | Mar 19 · Apr 3 · Apr 19 | Oct 22 · Nov 6 · Nov 22 | 216 days | 100% |
Planting calendar for Whippany
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 18 – May 24 |
| Tomatoes | Transplant outdoors | May 4 – Jul 7 |
| Peppers | Start seeds indoors | Mar 18 – Apr 18 |
| Peppers | Transplant outdoors | May 18 – Jun 18 |
| Eggplant | Start seeds indoors | Apr 4 – May 3 |
| Eggplant | Transplant outdoors | May 18 – Jun 18 |
| Cucumbers | Sow outdoors | May 18 – Jul 17 |
| Summer squash | Sow outdoors | May 4 – Jun 18 |
| Winter squash & pumpkins | Sow outdoors | May 18 – Jun 18 |
| Snap beans | Sow outdoors | May 4 – Aug 9 |
| Sweet corn | Sow outdoors | May 4 – Jul 7 |
| Watermelon & cantaloupe | Sow outdoors | May 18 – Jun 18 |
| Okra | Sow outdoors | May 11 – Jun 3 |
| Peas | Sow outdoors (spring) | Mar 18 – May 3 |
| Potatoes | Plant outdoors (spring) | Mar 18 – May 18 |
| Onions | Start seeds indoors (spring) | Feb 4 – Mar 3 |
| Onions | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (spring) | Feb 28 – Apr 3 |
| Broccoli | Transplant outdoors (spring) | Apr 4 – May 3 |
| Broccoli | Start seeds indoors (fall) | Jun 27 – Jul 7 |
| Broccoli | Transplant outdoors (fall) | Jul 27 – Aug 7 |
| Cabbage | Start seeds indoors (spring) | Feb 18 – Mar 18 |
| Cabbage | Transplant outdoors (spring) | Mar 18 – Apr 18 |
| Cabbage | Start seeds indoors (fall) | Jun 17 – Jul 17 |
| Cabbage | Transplant outdoors (fall) | Jul 17 – Aug 17 |
| Leaf lettuce | Sow outdoors (spring) | Mar 18 – Jun 3 |
| Leaf lettuce | Sow outdoors (fall) | Jul 17 – Sep 2 |
| Spinach | Sow outdoors (spring) | Mar 11 – Apr 24 |
| Spinach | Sow outdoors (fall) | Aug 3 – Sep 7 |
| Radishes | Sow outdoors (spring) | Mar 18 – May 8 |
| Radishes | Sow outdoors (fall) | Jul 17 – Sep 17 |
| Kale | Sow outdoors (spring) | Apr 4 – Apr 24 |
| Kale | Sow outdoors (fall) | Jul 10 – Aug 17 |
| Carrots | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Carrots | Sow outdoors (fall) | Jun 17 – Aug 2 |
| Garlic | Plant outdoors (fall) | Oct 17 – Nov 17 |
Where these dates come from
ZIP code 07981 is matched to the NOAA station Canoe Brook, NJ, 10.3 km away, at 180 ft elevation (27 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Canoe Brook, NJ (used) | 180 ft | Apr 18 | Oct 27 |
| Boonton 1 Se, NJ | 280 ft | Apr 17 | Oct 23 |
| Essex Fells Service Bldg, NJ | 350 ft | Apr 18 | Oct 24 |
| Caldwell Essex Co Ap, NJ | 173 ft | Apr 14 | Oct 28 |
Frost dates near Whippany
- Cedar Knolls, NJ 07927 · last Apr 18, first Oct 24
- Parsippany, NJ 07054 · last Apr 18, first Oct 24
- East Hanover, NJ 07936 · last Apr 18, first Oct 27
- Florham Park, NJ 07932 · last Apr 18, first Oct 27
- Morris Plains, NJ 07950 · last Apr 18, first Oct 24
- Convent Station, NJ 07961 · last Apr 18, first Oct 24
- Morristown, NJ 07963 · last Apr 18, first Oct 24
- Madison, NJ 07940 · last Apr 18, first Oct 27
Frequently asked questions
- When is the last frost in Whippany, NJ?
- For ZIP code 07981, the average last spring frost (32°F) is April 18, based on NOAA 1991-2020 climate normals for the Canoe Brook, NJ weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Whippany, NJ?
- The average first fall frost (32°F) is October 27. There is a 1-in-10 chance of frost by October 11, so tender plants are at risk from that point on.
- How long is the growing season in 07981?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 189 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.