Frost dates for Flemington 5 NNW, NJ
At Flemington 5 NNW, the median last spring frost (32°F) is Apr 24 and the median first fall frost is Oct 21, for a typical growing season of 179 days. For a 90% chance that the last frost has passed, wait until May 11. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Apr 24Last spring frost (median)50% chance of 32°F after this date
- May 11Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 179 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 21 | May 6 | May 22 |
| 32°F | Apr 9 | Apr 24 | May 11 |
| 28°F | Mar 27 | Apr 8 | Apr 25 |
| 24°F | Mar 10 | Mar 27 | Apr 9 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 29 | Oct 9 | Oct 24 |
| 32°F | Oct 6 | Oct 21 | Nov 5 |
| 28°F | Oct 16 | Nov 2 | Nov 16 |
| 24°F | Oct 30 | Nov 15 | Dec 1 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 137 days | 156 days | 177 days |
| 32°F | 157 days | 179 days | 201 days |
| 28°F | 182 days | 206 days | 225 days |
| 24°F | 210 days | 231 days | 253 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 08822 | 7a | 0 to 5°F | 6 km |
| 08801 | 7a | 0 to 5°F | 6 km |
| 08867 | 7a | 0 to 5°F | 7 km |
| 08809 | 7a | 0 to 5°F | 9 km |
| 08833 | 7a | 0 to 5°F | 10 km |
| 08829 | 7a | 0 to 5°F | 11 km |
| 08827 | 7a | 0 to 5°F | 13 km |
| 08825 | 7a | 0 to 5°F | 14 km |
| 08826 | 6b | -5 to 0°F | 16 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00283029, at 40.5739, -74.8817, elevation 81 m (265 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 124.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Wertsville 4 NE (16 km)
- Somerville Somerset Airport (19 km)
- Somerville 4 NW (20 km)
- Lambertville (24 km)
- Phillipsburg-Easton Brg (30 km)
- Belvidere Brg (33 km)
- Trenton Mercer Co Airport (33 km)
- Trenton State College (34 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.