Sometimes a certain tv channel range (example, 5.3 to 5.7) will not pick up on my tv. There is no obvious cause for it. Weather conditions are not a reliable predictor
Usually I get success after moving the antenna to various spots on the wall.
Same with my favorite FM 88.5 radio station. There's always some static, some days less, some days more. It changes as I move the wire antenna to different spots around the room. Putting it near the window is not necessarily optimum. Placement sometimes brings in the station at 88.3 stronger than the frequency I wish to hear.
I live 20 miles from the transmitting antennas. My apartment is at the inside corner of a building. Ground floor. Not the most favorable reception. It makes my reception inconsistent and dependent on good atmospheric conditions, though I'm not certain what those conditions need to be for good reception.