| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F | |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F | |
| Average First Frost Date: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 58h - Reading Prong | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 07945 - Mendham, NJ | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 17 | 19 | 27 | 36 | 46 | 54 | 59 | 58 | 51 | 38 | 31 | 23 | 38 |
| Avg Max Temp (°F) | 37 | 40 | 49 | 60 | 71 | 78 | 83 | 81 | 74 | 64 | 53 | 41 | 61 |
| Avg Precip (In.) | 4.18 | 3.05 | 4.23 | 4.47 | 4.97 | 4.52 | 4.97 | 4.49 | 5 | 4.04 | 4.28 | 3.96 | 52.16 |