USDA Hardiness Zone 7b
Frost Dates for 08628 — Ewing, New Jersey
NOAA 1991–2020 normals from Trenton Mercer Co Airport, NJ (184 ft), under a mile northeast.
Updated
In Ewing, the last spring frost (32°F) is around April 10 in half of years and has passed by April 25 in nine years out of ten. The first fall frost comes around November 1, as early as October 15 one year in ten, leaving a typical freeze-free season of 202 days (NOAA, Trenton Mercer Co Airport, NJ).
- Last spring frost
- April 10
- First fall frost
- November 1
- Growing season
- 202 days
- Hardiness zone
- 7b
50% probability
50% probability
freeze-free, 50%
5 to 10°F (-15.0 to -12.2°C) coldest night
- First snow
- December 6
- Last snow
- March 22
- Winters with snow
- 100%
- Snow per year
- 26.6"
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in Ewing
Half of springs at Trenton Mercer Co Airport, NJ see their last 32°F night by April 10; only one in ten is past it by March 30, and one in ten still has one after April 25. Planting tender crops after April 16 leaves a 30% risk of a frost on them, after April 20 20%, and after April 25 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 57% of the 56 New Jersey stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 1 in half of years, as early as October 15 one year in ten, and holds off past November 13 one year in ten. A hard freeze of 28°F follows 11 days later, around November 12; in spring the one-in-ten date for 28°F is April 12, 13 days before the 32°F one. The freeze-free season lasts 202 days in a typical year, longer than at 66% of the 56 New Jersey stations; it reaches 223 days one year in ten and falls short of 180 one year in ten. On average 97 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 15 days longer, to about April 25, and return around October 20. Severe cold of 16°F or below comes every winter, usually between December 25 and February 24.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 10 | Apr 15 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | May 1 | May 6 | May 11 |
| 32°F | Mar 30 | Apr 3 | Apr 5 | Apr 8 | Apr 10 | Apr 13 | Apr 16 | Apr 20 | Apr 25 |
| 28°F | Mar 16 | Mar 21 | Mar 25 | Mar 28 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 12 |
| 24°F | Feb 28 | Mar 6 | Mar 10 | Mar 14 | Mar 18 | Mar 21 | Mar 24 | Mar 28 | Apr 1 |
| 20°F | Feb 15 | Feb 24 | Feb 28 | Mar 4 | Mar 7 | Mar 10 | Mar 14 | Mar 18 | Mar 23 |
| 16°F | Jan 31 | Feb 7 | Feb 12 | Feb 18 | Feb 24 | Feb 28 | Mar 3 | Mar 8 | Mar 13 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 6 | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 2 |
| 32°F | Oct 15 | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 13 |
| 28°F | Oct 29 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 14 | Nov 18 | Nov 22 | Nov 29 |
| 24°F | Nov 9 | Nov 13 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 11 |
| 20°F | Nov 17 | Nov 25 | Nov 30 | Dec 3 | Dec 7 | Dec 11 | Dec 16 | Dec 22 | Dec 30 |
| 16°F | Dec 2 | Dec 9 | Dec 15 | Dec 21 | Dec 25 | Dec 31 | Jan 4 | Jan 9 | Jan 16 |
Freeze probabilities 1991–2020 at Trenton Mercer Co Airport, NJ, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 08628 →Compare Ewing with another place →
Weather by month in Ewing
July is the warmest month at Trenton Mercer Co Airport, NJ, averaging 86°F by day and 67°F at night; January is the coldest at 40°F and 24°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 86% of years.
Warmth for growing adds up to 3,551 growing degree days a year (base 50°F), more than at 55% of the 56 New Jersey stations. 33% of them (1,189) have built up by the end of June, and July adds the most, 815. Precipitation totals 45.7 inches a year, most in June (4.4") and least in February (2.7"); May to September bring 46% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 40 | 24 | 3.3 | 100% | 25 | 3 |
| Feb | 43 | 26 | 2.7 | 100% | 22 | 6 |
| Mar | 51 | 33 | 4.0 | 100% | 15 | 33 |
| Apr | 63 | 42 | 3.6 | 86% | 3 | 144 |
| May | 72 | 52 | 4.0 | 4% | <1 | 375 |
| Jun | 81 | 61 | 4.4 | 0% | 0 | 628 |
| Jul | 86 | 67 | 4.4 | 0% | 0 | 815 |
| Aug | 84 | 65 | 4.2 | 0% | 0 | 756 |
| Sep | 77 | 58 | 4.1 | 0% | 0 | 522 |
| Oct | 66 | 46 | 3.8 | 49% | 1 | 210 |
| Nov | 55 | 36 | 3.2 | 99% | 10 | 46 |
| Dec | 44 | 29 | 4.0 | 100% | 22 | 12 |
Monthly normals 1991–2020 at Trenton Mercer Co Airport, NJ (184 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Trenton State College, NJ, 2 miles east of Ewing, has a last frost 7 days later (April 17), a first frost 4 days earlier (October 28), a season 10 days shorter.
When it snows in Ewing, New Jersey
The first measurable snow (0.1 inch or more) in Ewing usually arrives around December 6, and the last of the season around March 22. Those are the middle dates across the winters of 1991–2020 at Trenton Mercer Co Airport, NJ, 0.9 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 19 days after the last snow.
Planting calendar for 08628
| When | What to do |
|---|---|
| January 30 – February 13 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 13 – February 27 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 13 – March 27 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 10 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 9 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 18 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 1 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 08628 is under a mile from Trenton Mercer Co Airport, NJ, which stands at 184 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 18940 (Newtown). The 2023 USDA Plant Hardiness Zone Map lists ZIP 08628 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across New Jersey →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.