August Was One of the Hottest Months in Denver History

If you felt like you were sweating your way through August, well, you probably were. Last month tied 2011 for the hottest August in Denver history, with an average temperature of 77 degrees.

Overall, 26 of August’s 31 days had a high temperature above 90 degrees, with temps on 17 of those days soaring past 95. To put this in perspective, in a typical summer, Denver will see 31 days of 90-plus-degree days. This year, we almost reached that milestone in just one month. Additionally, seven daily record-high temperatures were tied or broken in August.

At one point last month, Denver had 17 straight days of 90-degree heat—that’s just the fifth time in our history that we’ve seen a heat streak that lasted that long. So far this year, we’ve experienced a staggering 68 days of 90-degree heat, which makes 2020 the second hottest year on record, following 2012, which saw 72 days of temps over 90 degrees.

But summer isn’t (officially) over yet. We could still have a few more days where temps rise above 90 degrees. The average last date of a 90-degree temperature reading in Denver is September 4, and this weekend’s forecast calls for at least one day above 90.

If the heat alone didn’t have you seeking out the A/C, the lack of rain throughout August provided little relief. Denver only measured 0.35 inches of rain last month. Typically, we see 1.69 inches. This marks our fifth month in a row of below-average precipitation, which has only exacerbated the moderate to severe drought that’s currently affecting Colorado and created prime conditions for the intense wildfires that caused Denver to experience dangerous air quality.

Four major fires were sparked in August and continue to burn across the state with various degrees of containment. The Pine Gulch Fire, which is burning north of Grand Junction and is 79 percent contained, is now the largest wildfire in the state’s history. Earlier this week, officials determined that the Grizzly Creek Fire, east of Glenwood Springs, was “human-caused.” It’s now 73 percent contained. The Cameron Peak and Williams Fork fires are smaller, but still burning at zero and 10 percent containment, respectively.

So what’s driving this increase in temperatures? Climate change, of course. Let’s take a look at how “normal” temperatures are calculated: You take a 30-year average to find what is expected on a given day, month, or year. According to data from 1981 to 2010, Denver’s average August temperature is 72.5 degrees (that might seem low, but you also have to account for the drop in temperatures overnight).

Looking ahead to September, the normal temperature drops to 62.4 degrees, which means that we can expect more daytime highs in the 70s and more overnight lows in the 40s. But the Climate Prediction Center is anticipating a 40 percent chance of below-normal precipitation this month, which means that while we can expect a break from the merciless heat, the dryness we’ve been experiencing is likely to continue.