Planning Work Around the Weather

Weather changes the hazards on a jobsite in minutes: lightning, wind gusts, heat, ice, mud and flash floods. Crews that check the forecast and agree on stop-work limits ahead of time make safer decisions than crews deciding in the middle of a storm.

• Supervisors
• Outdoor workers
• Construction

Daily weather check

• Forecast high and low temperatures and the heat index or wind chill
• Chance and timing of thunderstorms
• Wind speed and gusts at working height
• Rain, snow or ice expected
• Any watches or warnings from the National Weather Service
• Who will monitor conditions during the day, and how the crew will be warned

Lightning

• When thunder roars, go indoors. If you can hear thunder, you’re close enough to be struck.
• Get into an enclosed building or a hard-topped vehicle. Job trailers and open sheds may not protect you.
• Wait 30 minutes after the last thunder before going back out.
• Get off roofs, steel, scaffolds, cranes, lifts and equipment, and away from open fields and water.
• Use a lightning-detection app or alert service on large sites.

Wind

• Cranes, aerial lifts, scissor lifts and suspended scaffolds all have manufacturer wind limits. Know them before the day starts. See Cranes and Aerial Lifts.
• Sheet goods (plywood, roofing, panels, glass) act like sails. Secure stockpiles and stop handling them in high wind.
• Wind at the top of a building or crane is stronger than on the ground.
• Brace new masonry walls and framing. See Masonry.

Heat and cold

• Heat: schedule heavy work early, increase water, rest and shade, and watch new workers closely. See Heat Illness.
• Cold: plan warm-up breaks, dress in layers, and clear ice from walkways, ladders and scaffolds. See Cold Stress.

Rain, mud and floods

• Rain weakens trench walls; the competent person must re-inspect after rain. See Excavation Inspections.
• Wet surfaces make ladders, roofs and steel slippery.
• Keep electrical cords and connections out of water. See Wet Locations.
• Never drive through flooded roads. See Flooded Roads.

Severe storms

Know where to shelter for tornadoes and severe storms, and secure loose materials before the storm arrives. See Severe Weather.

Last updated: October 2, 2026