Frost dates for Mount Sinai, NY
At Mount Sinai, the median last spring frost (32°F) is Apr 4 and the median first fall frost is Nov 7, for a typical growing season of 215 days. For a 90% chance that the last frost has passed, wait until Apr 19. Nearby ZIP codes are in USDA hardiness zones 7a to 7b.
- Apr 4Last spring frost (median)50% chance of 32°F after this date
- Apr 19Safer planting date10% chance of 32°F after this date
- Nov 7First fall frost (median)50% chance of 32°F by this date
- 215 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 6 | Apr 20 | May 7 |
| 32°F | Mar 23 | Apr 4 | Apr 19 |
| 28°F | Mar 11 | Mar 27 | Apr 7 |
| 24°F | Mar 1 | Mar 16 | Mar 31 |
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 | Oct 10 | Oct 26 | Nov 10 |
| 32°F | Oct 20 | Nov 7 | Nov 24 |
| 28°F | Nov 2 | Nov 22 | Dec 9 |
| 24°F | Nov 18 | Dec 6 | Dec 24 |
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 | 165 days | 187 days | 210 days |
| 32°F | 195 days | 215 days | 236 days |
| 28°F | 217 days | 241 days | 262 days |
| 24°F | 240 days | 264 days | 288 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 |
|---|---|---|---|
| 11766 | 7b | 5 to 10°F | 1 km |
| 11776 | 7b | 5 to 10°F | 3 km |
| 11764 | 7b | 5 to 10°F | 4 km |
| 11789 | 7b | 5 to 10°F | 5 km |
| 11727 | 7b | 5 to 10°F | 6 km |
| 11778 | 7b | 5 to 10°F | 7 km |
| 11953 | 7a | 0 to 5°F | 7 km |
| 11784 | 7b | 5 to 10°F | 7 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 USC00305606, at 40.9331, -73.0192, elevation 15 m (50 ft).
- Data quality: Representative (10+ years), 10 years of freeze data.
- Average days per year at or below 32°F: 79.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Setauket Strong (8 km)
- Upton COOP - Nwsfo New York (15 km)
- Islip Li Macarthur Airport (17 km)
- Shirley Brookhaven Airport (18 km)
- Baiting Hollow (23 km)
- Molloy Cercom (24 km)
- Riverhead Rsch Farm (26 km)
- Centerport (30 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.