Frost dates for Westerly State Airport, RI
At Westerly State Airport, the median last spring frost (32°F) is Apr 11 and the median first fall frost is Oct 31, for a typical growing season of 201 days. For a 90% chance that the last frost has passed, wait until Apr 26. Nearby ZIP codes are in USDA hardiness zones 6b to 7b.
- Apr 11Last spring frost (median)50% chance of 32°F after this date
- Apr 26Safer planting date10% chance of 32°F after this date
- Oct 31First fall frost (median)50% chance of 32°F by this date
- 201 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 14 | Apr 27 | May 10 |
| 32°F | Mar 31 | Apr 11 | Apr 26 |
| 28°F | Mar 14 | Mar 29 | Apr 10 |
| 24°F | Mar 3 | Mar 18 | 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 4 | Oct 17 | Nov 1 |
| 32°F | Oct 16 | Oct 31 | Nov 12 |
| 28°F | Oct 28 | Nov 11 | Nov 28 |
| 24°F | Nov 10 | Nov 25 | Dec 10 |
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 | 155 days | 173 days | 195 days |
| 32°F | 181 days | 201 days | 221 days |
| 28°F | 207 days | 227 days | 250 days |
| 24°F | 233 days | 252 days | 275 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 |
|---|---|---|---|
| 02891 | 7a | 0 to 5°F | 1 km |
| 06379 | 7a | 0 to 5°F | 5 km |
| 02808 | 7a | 0 to 5°F | 8 km |
| 02804 | 6b | -5 to 0°F | 10 km |
| 06378 | 7a | 0 to 5°F | 10 km |
| 02813 | 7a | 0 to 5°F | 12 km |
| 02894 | 6b | -5 to 0°F | 13 km |
| 06359 | 6b | -5 to 0°F | 15 km |
| 02833 | 6b | -5 to 0°F | 15 km |
| 02807 | 7b | 5 to 10°F | 27 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 USW00014794, at 41.3497, -71.7989, elevation 25 m (81 ft).
- Data quality: Representative (10+ years), 19 years of freeze data.
- Average days per year at or below 32°F: 109.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Kingston 1 W (26 km)
- Kingston (26 km)
- Kingston 1 NW (27 km)
- Coventry 2 (41 km)
- Newport Rose (41 km)
- Newport State Airport (48 km)
- Providence T F Green Airport (51 km)
- N Foster 1 E (57 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.