Wind-driven dust cut visibility and pushed air quality into hazardous ranges in parts of the Upper Midwest.

Officials say more severe weather could hit the state again Tuesday with large hail, damaging winds and a few tornadoes possible.

Officials are urging travelers to watch conditions closely as heat, smoke and outdoor hazards threaten summer trips across the Rockies and Northern Plains.

Warm temperatures, gusty winds, and fast snowmelt are creating fire danger in eastern Montana and flood risk in the south-central part of the state.

Officials in two South Dakota cities say warning systems need repairs, upgrades and temporary workarounds.

Forecasters say the Northern Plains could see supercells, large hail and strong winds from Tuesday into Wednesday.

Election officials said polling sites would stay open while residents were urged to check weather, roads and voting locations before heading out.

The National Weather Service watch covers much of the Northern Plains as summer travel ramps up.