Monsoon moisture will be on the increase later this week. This will bring a chance at thunderstorms producing rain but also lightning strikes. There appears to be enough moisture that these thunderstorms will not be dry, and some locally heavy rain is possible. Lightning strikes are a guarantee, and since the forests are dry and the temperatures have been hot, the fire danger will remain high. New lightning sparked wildfires are a possibility later this week and through the weekend. At the very least, the monsoon moisture will produce more cloud cover which will keep temperatures down somewhat. Without the partial cloud cover, the sun would be more intense and temperatures would be hotter.
A weak cold front will slip south from Canada by Tuesday morning. This front will not really cool things off, but keep temperatures steady. Afternoon highs will mainly be in the low to mid 90s, a few places will top out in the 80s. There will be a few clouds but no precipitation. The wind will be light from the northeast. Wednesday the feed of monsoon moisture will move into western and central Montana. Clouds will increase so much that skies will be partly to mostly cloudy, keeping the temperatures in the 80s and 90s. Without the clouds, temperatures would likely climb over 100. A few thunderstorms will develop late in the afternoon and evening, and the threat of storms will continue through the night. Thursday will be partly cloudy with a few isolated thunderstorms in the afternoon. These storms will have some moisture to work with, but they will also produce lightning strikes. Highs will be in the 80s and 90s. Friday will be similar with isolated afternoon storms. An increase in moisture and thunderstorms are likely for Saturday. Storms could be widespread for much of the state, and temperatures will be more in the 80s because of this. Some heavy rain with thunderstorms is possible through the night. Sunday will be mostly sunny with an isolated storm, highs near 90.
Have a great day.