What if you could know the state of geomagnetic weather with a real magnetometer made from a 2-Liter soda bottle and a laser pointer, and yes, a small magnet that you may well have already.
Here's the detailed "how to do it", and how to compare your own K index with NASA:
All we need now is an easy solar flux device, and we're all set! -but we do have easy sunspot photos, with a howto right here on The Hambone!