The official National Weather Service forecast for Rillito — 32.4148°N, 111.1562°W, 8.6 miles from I-10. Forecasts here are written by NWS TWC, this county’s forecast office.
| Pima County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 66 | 69 | 75 | 82 | 91 | 100 | 100 | 98 | 95 | 86 | 75 | 66 | 84 |
| Avg low °F | 38 | 40 | 44 | 50 | 57 | 67 | 73 | 72 | 67 | 55 | 45 | 38 | 54 |
| Precip in | 0.9 | 0.9 | 0.6 | 0.3 | 0.1 | 0.2 | 2.3 | 2.3 | 1.3 | 0.6 | 0.5 | 1.0 | 11.0 |
1996–2025 normals for Pima County — the climate division Rillito sits in. All-time county record high 113.8°F (1990-06-27); record low 16.2°F (1978-12-08). Source: NOAA / National Weather Service.