THE CLARK FORK WATERSHED IS GETTING HOTTER: The trends seen globally and nationally are observed right here in our basin.  since 1950, average temperatures in our area have increased about 1 degree in the Kalispell area, and closer to 2 degrees in Butte and Missoula. Notable details from temperature records show that our minimum temperatures are increasing a bit more than maximum temperatures, which can impact when and where snow falls.  Plus, January and March are the months with the largest increase in temperatures.  The data from our basin fits predictions that western North America is likely to warm more than the global average, and that this warming is likely to be more pronounced during the winter.

IN PLAIN WORDS? Temperatures in western north America, on average, are 1.4 degrees warmer than 50 years ago.  Globally, 11 of the years between 1995 and 2006 ranked among the 12 warmest of the last century.  And in the future?  it’s likely going to get even warmer.  If greenhouse gas emissions continue to increase, and factoring in all other natural causes, the consensus of a suite of climate models predicts an additional temperature increase of more than 5 degrees Fahrenheit over the rest of the century.

AND IN THE FUTURE? It’s likely going to get even warmer. If greenhouse gas emissions continue to increase, and factoring in all other natural causes, the consensus of a suite of climate models predicts an additional temperature increase of more than 5 degrees Fahrenheit over the rest of the century.

IN THE CLARK FORK BASIN, most of the trends we see now have only become distinct over the past two decades.  While it will likely take more time before our climate trends are deemed statistically significant, we can augment local observations with records from neighboring western states, from north America, and from the around the globe.  Combined, this vast amount of data points to more than just wild weather fluctuations—it shows that we’re living in a changing climate.

STRETCHING OUR GROWING SEASON? If you’ve been the proud gardener of tasty red tomatoes lately instead of a bumper crop of green ones, you might have noticed that western Montana’s growing season Is longer.  Missoula, for instance, gained 15 more frost-free days over the past 50 years.  in fact, just between 1990 and 2006, the USDA plant hardiness zones shifted by one full zone throughout most of our watershed (hardiness zones are based on average annual low temperatures, designated in 10-degree increments).