Monday will be another mostly blue-sky day with very warm temperatures for this time of year. A few mid 70s readings are possible, which could set daily high temperature records.
Tuesday sees changes as a storm system off the Pacific coast sends a wave of showers our direction along with a cold front. Expect much cooler temperatures with highs only in the 50s on Tuesday. A few mountain passes could see snowflakes. Rainfall totals will be light with isolated areas seeing a quarter of an inch or greater.
Looking longer term, expect another wave of moisture from that storm system off of the coast to impact Northwest Montana on Thursday. At the moment, areas north of I-90 should expect showers that day. Yet another round of rain is expected late next weekend. Temperatures later in the week will be in the upper 50s to mid 60s; near normal for this time of year.