Bay City, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 60.5 °F (low) to 79.6 °F (high). Annual precipitation averages 49.1 Inches. Bay City is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 44.0 °F | 63.8 °F | 3.7 in. |
| February | 47.8 °F | 67.4 °F | 2.65 in. |
| March | 53.9 °F | 73.2 °F | 3.16 in. |
| April | 59.8 °F | 78.9 °F | 3.23 in. |
| May | 67.7 °F | 85.0 °F | 4.42 in. |
| June | 73.3 °F | 90.1 °F | 5.55 in. |
| July | 74.5 °F | 91.8 °F | 3.86 in. |
| August | 74.3 °F | 93.2 °F | 4.52 in. |
| September | 70.4 °F | 89.2 °F | 5.48 in. |
| October | 61.4 °F | 82.8 °F | 4.88 in. |
| November | 52.3 °F | 73.4 °F | 3.85 in. |
| December | 46.0 °F | 66.1 °F | 3.76 in. |
| Annual | 60.5 °F | 79.6 °F | 49.06 in. |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |