Billings and surrounding areas
Billings Area: Scattered spring showers will hold out through much of the day along with overcast skies. This damp, cool weather pattern will stay in the region through at least early Tuesday. Thereafter, the atmosphere becomes a bit more settled, drier and warmer through the middle of the week.
Montana: Again today through early in the week, the main energy and weather activity will be to the east, with the plains and areas east of the Continental Divide in position to receive more moisture. Further west, a passing shower or perhaps a thunderstorm cannot be ruled out through Tuesday, but they will likely be very isolated. Otherwise expect partly to mostly cloudy skies to the west through the middle of the week.
Wyoming: Temperatures will cool off for the first few days of the week, compliments of a trough in place across the region. Scattered showers are possible today, with the best chance for precipitation likely in the northern half of the state, with more isolated showers elsewhere. The moisture in the atmosphere will likely give way to morning fog in places on Tuesday, with then gradually clearing skies and only slight chance for late day showers and thunderstorms.
Yellowstone: Widely scattered light showers are still a possibility throughout the day, especially early on and then again on Tuesday. It will also be a cool start to the week, with temperatures cool enough for perhaps some light snow to fall.
Bighorn Canyon: Decent atmospheric moisture could produce a widely scattered shower throughout the day with continued mostly cloudy skies. Tuesday looks drier, but early morning fog could easily form.