Denver hits record-high temperature for second day in a row after one of warmest summers on record

DENVER – Denver hit record high temperatures Thursday and Friday as a mid-September heat wave gripped most of the state and West after one of the warmest summers on record.

Denver had reached 99 degrees just after 3:30 p.m. and had broken the daily high temperature record of 93 degrees when the airport hit 94 at 12:06 p.m. The previous record was set in 2018 and the National Weather Service said temperatures could reach 100 degrees Friday afternoon.

On Thursday, Denver hit 96 degrees, topping the record of 94 set in 1994.

The temperature is the hottest recorded this late in the year in Denver, according to Denver7 Chief Meteorologist Mike Nelson, who adds that Denver is experiencing 15 more days above 95 degrees per year than it did in 1970 as carbon dioxide continues to build in the atmosphere. The top five years with the most 95+ degree days have all occurred in the past decade.

MORE: 360 in-depth on Colorado climate change: Mike Nelson breaks down the science

The normal maximum temperature for the first 10 days of September is 83.5 but has been more than 4 degrees above normal so far this year.

High temperatures were also possibly going to break records for Fort Collins, Akron, Dillon, Colorado Springs, Pueblo and Grand Junction on Friday, according to the National Weather Service in Boulder.

Denver has now reached 90 degrees 55 times this year, putting it tied for seventh on the most ever for a year. Last year, Denver had 75 days of 90 degrees or more – the most ever.

Denver reached 100 degrees five times already this year. There have only been two September days in recorded history when temperatures have hit 100 – on Sept. 5, 2020 and Sept. 2, 2019. “Today will be close,” NWS forecasters wrote Friday morning.

According to data released Thursday by the National Oceanic and Atmospheric Administration, this June to August in Colorado was the fourth-warmest on record and in the top 25% of the driest summers over the past 127 years.

That was a trend that continued across the U.S. West, as California, Oregon, Nevada, Idaho and Utah all saw their warmest summers on record. Arizona, Montana and Washington all saw their second-warmest, while Wyoming saw its third-warmest June-August period since 1895.

As climate change continues to exacerbate extreme weather conditions in Colorado, the state has seen many of its warmest years on record over the past 20 years. Among the top 22 years with the most 90-degree days in Denver, 16 of them have occurred since 2000.

MORE: A look ahead at September and the rest of fall season in Colorado

New research from scientists at National Jewish Health and the Union of Concerned Citizens published Thursday in the Journal of Exposure Science and Environmental Epidemiology says that climate change causing the higher temperatures across the Denver area has increase ground-level ozone levels as well. There was another air quality health advisory for ozone levels Friday across the metro area – which has been typical for the past two months.

The heat has brought back drought conditions to parts of the eastern half of Colorado that have been drought-free for most of the summer, though monsoon moisture has continued to improve conditions in southwestern Colorado.

Denver and parts of the northern metro area are back into the abnormally dry category, as are parts of the northeastern plains. Parts of Washington, Yuma and Logan counties are now experiencing moderate drought.

Forecasts show it is likely Denver will top 90 degrees again on Saturday before a moderate cooldown Sunday and Monday before a cold front hits Tuesday, bringing expected rain and high temperatures in the 70s.

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