Weather records- Design and build an automatic recording weather device. Test it over a period of time. How do other materials compare in expansion and contraction. Effects of temperature on viscosity of oil, chemical reactions, Brownian movement, burning of different materials. Does the amount of particle pollution vary with distance from a road, with location, with height.
Light is Affected passing through water e.g. viewing objects under water, formation of rainbows.
Can you measure how much dew is formed in a square meter. Can you construct your own thermometer to keep your own records. Measure the rainfall over a period of time and compare it with the daily weather reports.