What you need:
Bucket (with no holes!)
Pull on some wellies and macs and get outside today to make a rain gauge. Take an old bucket and mark centimetres inside with a permanent marker. Place in an open space outside and every day take a rain level reading. Keep a note of your readings and also weather observations in your notebook. After a few weeks of collecting data you may start to notice some patterns and be able to predict the weather a few hours in advance.