Frost dates for Bangor Intl Airport, ME
At Bangor Intl Airport, the median last spring frost (32°F) is May 4 and the median first fall frost is Oct 4, for a typical growing season of 152 days. For a 90% chance that the last frost has passed, wait until May 17. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 4Last spring frost (median)50% chance of 32°F after this date
- May 17Safer planting date10% chance of 32°F after this date
- Oct 4First fall frost (median)50% chance of 32°F by this date
- 152 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 | May 5 | May 17 | May 31 |
| 32°F | Apr 24 | May 4 | May 17 |
| 28°F | Apr 11 | Apr 23 | May 4 |
| 24°F | Mar 31 | Apr 12 | Apr 24 |
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 13 | Sep 25 | Oct 7 |
| 32°F | Sep 23 | Oct 4 | Oct 21 |
| 28°F | Oct 1 | Oct 17 | Nov 2 |
| 24°F | Oct 14 | Oct 31 | Nov 14 |
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 | 111 days | 129 days | 148 days |
| 32°F | 134 days | 152 days | 170 days |
| 28°F | 156 days | 175 days | 196 days |
| 24°F | 180 days | 200 days | 219 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 |
|---|---|---|---|
| 04401 | 5a | -20 to -15°F | 6 km |
| 04412 | 5a | -20 to -15°F | 7 km |
| 04444 | 5a | -20 to -15°F | 13 km |
| 04474 | 5a | -20 to -15°F | 13 km |
| 04419 | 5a | -20 to -15°F | 15 km |
| 04450 | 5a | -20 to -15°F | 16 km |
| 04456 | 5a | -20 to -15°F | 17 km |
| 04496 | 5a | -20 to -15°F | 18 km |
| 04429 | 5a | -20 to -15°F | 18 km |
| 04416 | 5a | -20 to -15°F | 20 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 USW00014606, at 44.7978, -68.8186, elevation 45 m (148 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 161.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Orono (16 km)
- Old Town 2 W (17 km)
- Corinna (36 km)
- E Surry (44 km)
- Belfast (47 km)
- Dover-Foxcroft Wastewater Plant (52 km)
- E Sangerville (52 km)
- Harmony (60 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.