All truly great thoughts are conceived by walking.
Pay attention to weather forecasts and avoid being caught on exposed ridges or above treeline during electrical storms. Know an escape route in case fast-moving storms catch you off-guard.
If a storm hits, spread your group out and keep track of each other so if one person is hit, others can help.
If you don't have time to get to a lower elevation, squat down to reduce your height and minimize your contact with the earth. Take off your pack if it has a metal frame. If you have a foam pad, put it under you.
In spring and after heavy rains, streams can change from trickles to torrents, making crossings difficult. If you ford a stream, be extremely careful.
Use common sense and, if in doubt, don't cross.
IN THE WHITE MOUNTAINS:
Rain, snow and fog are possible at any time of the year. Remember that weather in the mountains is generally colder and more severe than in the valleys—and the weather can changing quickly.