Junction City, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 40.8 °F (low) to 70.9 °F (high). Annual precipitation averages 34.6 Inches. Junction City is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 32.9 °F | 48.7 °F | 6.54 in. |
| February | 33.1 °F | 54.6 °F | 5.28 in. |
| March | 34.9 °F | 60.9 °F | 4.72 in. |
| April | 37.4 °F | 67.4 °F | 2.07 in. |
| May | 42.9 °F | 76.7 °F | 1.4 in. |
| June | 47.8 °F | 85.4 °F | 0.79 in. |
| July | 53.9 °F | 95.5 °F | 0.19 in. |
| August | 52.2 °F | 95.1 °F | 0.16 in. |
| September | 46.5 °F | 88.7 °F | 0.31 in. |
| October | 39.6 °F | 74.1 °F | 1.56 in. |
| November | 36.1 °F | 56.5 °F | 3.93 in. |
| December | 32.5 °F | 46.7 °F | 7.63 in. |
| Annual | 40.8 °F | 70.9 °F | 34.58 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |