The official National Weather Service forecast for Ellicott City — 39.2673°N, 76.7983°W, 2.6 miles from I-70. Forecasts here are written by NWS LWX, this county’s forecast office.
| Howard County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 42 | 46 | 55 | 66 | 74 | 83 | 87 | 85 | 78 | 67 | 56 | 46 | 65 |
| Avg low °F | 25 | 27 | 33 | 43 | 52 | 61 | 66 | 64 | 58 | 46 | 36 | 29 | 45 |
| Precip in | 3.1 | 2.8 | 3.5 | 3.6 | 4.6 | 4.5 | 4.5 | 4.2 | 4.5 | 3.9 | 3.0 | 3.7 | 45.9 |
1996–2025 normals for Howard County — the climate division Ellicott City sits in. All-time county record high 101.2°F (1988-07-17); record low -9.4°F (1982-01-17). Source: NOAA / National Weather Service.