The official National Weather Service forecast for Rio Grande City — 26.3798°N, 98.8203°W, population 47,070, 26.6 miles from I-2. Forecasts here are written by NWS BRO, this county’s forecast office.
| Starr County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 71 | 76 | 82 | 88 | 94 | 98 | 98 | 100 | 94 | 88 | 79 | 72 | 87 |
| Avg low °F | 48 | 52 | 59 | 65 | 71 | 75 | 76 | 76 | 72 | 65 | 57 | 50 | 64 |
| Precip in | 0.7 | 0.7 | 1.3 | 1.4 | 2.6 | 2.2 | 2.3 | 1.8 | 4.4 | 1.8 | 1.4 | 0.9 | 21.5 |
1996–2025 normals for Starr County — the climate division Rio Grande City sits in. All-time county record high 110.9°F (2023-06-20); record low 12.1°F (1962-01-12). Source: NOAA / National Weather Service.