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SUMMARY FOR POLICYMAKERS
In this report, we examine the historical observations of weather and climate in Montana. We find that climate variability from year-to-year and decade-to-decade plays a significant role in Montana’s climate.
While temperatures have generally appeared to have risen across the state over the past century (although part of this rise may be a result of non-climatic influences on the thermometers), precipitation changes have been largely limited to the early portion of the 20th century, and other climate impacts, such as drought, wildfires, and glacier changes are largely influenced by natural variations and cycles driven in part by decadal variations in the Atlantic and Pacific Oceans. Further, “tropical” disease such as malaria or the West Nile Virus are not so much influenced by the climate as they are by the (already extant) and widespread presence of the host species.