Colorado is the kind of place where you can play softball in shorts in 70-degree weather in the morning, then bundle up and brace for a blizzard by nightfall. The state's weather is so variable that one winter will leave a giant snowpack in the Rockies, and the next, like the last one, will be bone dry and prime the forests for devastating wildfires when the summer heat arrives.
Even in a relatively quiet year, Colorado's weather keeps the state climatologist, Nolan Doesken, very busy. This year, with a prolonged drought, record-breaking heat in the spring and early summer, and massive wildfires in June, Doesken has been going nonstop for months.
Doesken has been studying the state's climate since 1977, when he arrived at Colorado State University's Colorado Climate Center in Fort Collins. He was appointed state climatologist in 2006 and is a former president of the American Association of State Climatologists. Over the years he has not only recorded his state's wild extremes, he's also been in the middle of some, including a rainstorm that dumped 14 inches in a day, and an early fall snowstorm that left him stranded in a car on a highway.
InsideClimate News spoke via email with Doesken about his job.
ICN: You've been watching Colorado's climate for decades. Has it changed noticeably since you started?
Doesken: The most notable change that has been evident over the past 20 years has been warmer temperatures at most times of the year, but particularly a lack of extreme wintertime cold waves. Some of our mountain valleys used to see temperatures below 40 degrees Fahrehneit fairly regularly, a few times every few years. Now we've only seen those conditions once or twice in the past two decades. We had been seeing a lot of hot temperatures but without extreme heat waves—although this year we got the extreme heat wave, similar to what we had back in 1934 and 1954 but had not seen for many, many years.
We haven't seen any systematic changes toward wetter or drier—or greater extremes in storms and precipitation—or at least not yet.
ICN: How much of Colorado is under severe drought?
Doesken: 100 percent of our state is currently assessed as being in severe, extreme or exceptional drought. Most of our mountains had much below average winter snow followed by an unusually warm and dry spring and a blistering hot summer. A few local areas have enjoyed beneficial rains during the past seven weeks thanks to the summertime North American monsoon. Fortunately, that put a damper on wildfires that were raging in many parts of the state in June.
ICN: Is this unprecedented?
Doesken: We had similar conditions back in 2002, 1977, 1954 and 1934. This year was so hot that conditions were on their way to being as bad or worse than in those famous droughts, but the July rains really helped, especially in the mountains.
ICN: What are some of the less-obvious impacts of drought that might escape the average person?
Doesken: There are areas of the state that rely on groundwater for water supplies. During drought, the depletion of groundwater is accelerated, and that can have significant long-term impacts.
This year we had so much forest fire smoke (a drought impact) and ash in the air that it clogged some air filters on air conditioners resulting in more maintenance and repairs.
Drought is a slow disaster that actually has apparent impacts on mental health for those who are facing economic hardship or those who are living with the constant stress from potential wildfire. Drought really wears on you.
ICN: How many heat records have been set in Colorado this year? Has this been the state's hottest year so far?
Doeksen: Quite a few, but we only track the "new records" for selected stations that have very long and consistent climate data. So far (counting August) 7 out of 8 months this year have been warmer than average over many areas of Colorado. For most of the state, this will be the warmest Jan.-Aug. on record.
ICN: Has there been a big change in the nighttime lows Colorado has been experiencing in recent years?
Doesken: Yes. Overnight lows have been showing a warming trend in the past 20 to 30 years. Interestingly, this year it has been the daily highs, more so than the lows, that have been unusually high.
ICN: What has been the most memorable weather event in the state since you've been there?