Forecast for the weekend: hot and dry Sat and Sun, cooler by Sun night into Mon

06/20/25 9am: Happy first day of astronomical summer! The Summer solstice is official at 8:42pm this evening. In fitting fashion we have our first summer heat wave of the season today through Sun. Its already 80 degs at my house before 9am and high temps will be near or above 100 degs today for much of Den/Bou and the front-range, eastern plains and western slope. The other big story for today will be the strong wind, especially over western CO and that will lead to high fire danger in spots.

Relief will come late Sun night into Mon as a cold-front moves in from the north / northwest, especially impacting the front-range (Den/Bou), much cooler with temps in the 70s by Mon with much better rain chances.

First for today and tomorrow:All of the front-range (Den/Bou) below 6k ft and all of the eastern plains of CO are under a Heat Advisory from 11am today through 6pm Sat for temps near/above 100 degs. It will also be windy at times today with southwesterly wind-gusts of 15-30mph, less wind tomorrow. Cooler but still hot on Sun.

All of western CO (west of Vail Pass to BV) is under a Red Flag Warning for today from 9am-11pm: hot and dry conditions with southwest wind-gusts of 30-60 mph, strongest over western / northwest CO. Also a Red Flag Warning in place for tomorrow (Sat) as well 9am-11pm again, wind likely not a strong but still some wind-gust of 20-50mph in spots. Fire Weather Watch through Sat pm as well (no burning).

Hottest days will be today (Fri) and Sat. The big ridge of high-pressure starts moving east of CO by Sun so still warm but not quite as hot. As the ridge moves east a large trough pattern devlopes over the western U.S. and that will usher in cooler and more unsettled weather next week (in fact some snow for northwest WY and parts of WY Sat night into Sun/Mon.

As I mentioned a cold-front will move down the front-range after 9pm Sun (and across northern CO). That will set the stage for much better thunderstorm chances on the front-range Mon afternoon, mostly after 3pm (but temps will be much cooler).

For the mountains hot through Sat a bit cooler and breezy on Sun but will remain dry. Cooler by Mon but likely dry as the moisture and storms are forecast to be on the front-range again (east of the Cont. Divide)

Looking ahead, I see a surge of monsoon like moisture (remnants of hurricane Erik near southern MX) will likely work its way into CO by Tue/Wed of next week... best / deepest moisture likely over southern CO (San Juans) and over parts of the front-range, but better rain chances for north-central CO as well, especially Tue, Wed and Thu afternoons next week, after 2pm on each day. More on that later..

First image loop shows forecast wind-gusts over the next 48hrs (6am this morning to 6am Sun) from latest HRRR. Second image shows all the current Heat Advisories (orange) and Red Flag Warnings / Fire Weather Watches in Red. Image 3 shows forecast high-temps for today. Image 4 shows the cold-front moving into northern CO and down the front-range at 3am Mon from latest GFS.