isohel
/ˈaɪsəhɛl/
noun
- A line on a map connecting points that receive the same amount of sunshine.
- The isohel on the weather map showed that the coast gets more sun than the mountains.
- Farmers use isohels to decide which crops will grow best in different areas.
- The isohel for 2,500 hours of sunshine per year runs through the southern part of the state.