First mod makes the heat shimmer effect (Like in Egypt) show up at 80 degrees instead of the rare 90 degrees.
Second mod makes the lightning strikes happen more often, with less time between strikes (but not too much), and a higher chance that any given lightning strike will be on the currently active lot instead of in the distance. Also increases the chance of rainbows.
These mods modify two different files, so they are compatible with each other.
More Heat Shimmer