| 2023 Hardiness Zone: | Zone 9b: 25°F to 30°F Zone 10a: 30°F to 35°F | |
| 2012 Hardiness Zone: | Zone 9b: 25°F to 30°F | |
| 1990 Hardiness Zone: | Zone 9b: 25F to 30F | |
| Average First Frost Date: | Dec. 11 - Dec. 20 | |
| Average Last Frost Date: | Feb. 11 - Feb. 20 | |
| Koppen-Geiger Climate Zone: | BSh - Hot Semi-Arid Climate | |
| Ecoregion: | 31d - Rio Grande Floodplain and Terraces | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 181 - 210 days Over 86°F |
Annual Climate Data for ZIP Code 78582 - Rio Grande City, TX | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 44 | 48 | 56 | 62 | 70 | 73 | 74 | 74 | 71 | 62 | 54 | 46 | 61 |
| Avg Max Temp (°F) | 69 | 74 | 82 | 88 | 92 | 97 | 99 | 99 | 94 | 87 | 78 | 70 | 86 |
| Avg Precip (In.) | .96 | 1.1 | .74 | 1.31 | 2.47 | 2.92 | 1.29 | 2.08 | 4.63 | 2.47 | .91 | .94 | 21.82 |