Maine frost dates by city
| City | Last frost (50%) | Safer date (10%) | First frost (50%) | Season |
|---|---|---|---|---|
| Bangor | May 4 | May 17 | Oct 4 | 152 days |
| Portland | Apr 26 | May 7 | Oct 15 | 170 days |
Each city uses its nearest major NOAA weather station, usually the airport. Valleys, hilltops and rural spots can differ from it by one to three weeks. How to read these dates.