Amish don't have Weather Channel. No apps. They have: sky, wind, pressure (feel it in joints), animal behavior.
Signs
Cows lie down — rain coming. Swallows fly low — storm coming. Red sunset — tomorrow clear. Ring around moon — rain in 2 days. Cat washes face — guests coming (okay, that's not weather).
Accuracy
Amish farmers predict tomorrow's weather with 70-80% accuracy. Weather service — 80-85%. Difference — 5-10%. While the farmer looks at the sky, the weather service looks at a $50 million supercomputer.