Weather information for the New Castle area is provided below. Average temperatures, climate details and current forecasts are included.
Monthly average temperatures and precipitation for New Castle are shown below.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
| Avg. High | 34° | 36° | 47° | 58° | 70° | 78° | 84° | 81° | 74° | 64° | 50° | 38° |
| Avg. Low | 15° | 15° | 24° | 34° | 44° | 54° | 58° | 56° | 50° | 37° | 30° | 21° |
| Daily Avg | 24° | 26° | 36° | 46° | 58° | 66° | 71° | 68° | 64° | 51° | 41° | 30° |
| Avg. Precip. | 2.3 in | 2.1 in | 3.1 in | 3.0 in | 3.5 in | 4.1 in | 4.0 in | 3.4 in | 3.5 in | 2.7 in | 3.1 in | 2.8 in |
| Note: All temperatures are in degrees Fahrenheit. | ||||||||||||
