The official National Weather Service forecast for Royse City — 32.9751°N, 96.3325°W, population 13,922, 2.1 miles from I-30. Forecasts here are written by NWS FWD, this county’s forecast office.
| Rockwall County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 56 | 60 | 68 | 75 | 83 | 90 | 95 | 96 | 89 | 79 | 67 | 58 | 76 |
| Avg low °F | 35 | 39 | 47 | 54 | 63 | 71 | 74 | 74 | 67 | 55 | 46 | 38 | 55 |
| Precip in | 2.7 | 2.8 | 3.8 | 3.5 | 5.0 | 3.9 | 2.0 | 2.4 | 2.7 | 4.4 | 3.2 | 3.1 | 39.5 |
1996–2025 normals for Rockwall County — the climate division Royse City sits in. All-time county record high 109.2°F (2011-08-04); record low -0.1°F (2021-02-16). Source: NOAA / National Weather Service.