Rule 31 of 40 · Chapter V — Water, Weather, and Place
Never work live gear in rain
Why this rule exists
Rain removes your margins all at once: it wets your skin, tools, equipment, and the ground you stand on, and gives fault current a conductive film to travel. Water tracking across an energized surface can flash to ground through a path that would not exist dry, including through you. Add reduced visibility, cold-numbed hands, and slick footing, and the odds of a slip into a live part climb just as the consequences worsen. There is rarely a good reason to open energized equipment in falling rain. The weather itself is a hazard multiplier.
In practice
If it is raining, de-energize before opening outdoor equipment, and keep the interior dry while you work; tent or shelter it. Do not rely on a quick hot fix in the wet; the quick jobs are where people get caught. Dry your hands and tools, stand on a dry insulating surface, and postpone non-urgent work until conditions improve. For anything that genuinely cannot wait, treat it as energized work in a wet location: full rated PPE, GFCI protection, and ideally a second qualified person. When in doubt, wait for dry.
When it doesn't apply
True emergencies, a downed line, a life-safety failure, sometimes force work in bad weather, and that is exactly when utility and trained emergency crews should handle it, not a DIYer. Restoring power to end a mild inconvenience is not an emergency. If the only pressure to work in the rain is impatience, shelter the job or wait.