Denver Sets New Record for 90° Days

[donsutherland1]

Today, Denver hit 90°. That was the 74th time this year that the temperature reached or exceeded 90° at Denver. The prior record was 73 days, which was set in 2012.

The five highest number of 90° days during a year are:
1. 74, 2020
2. 73, 2012
3. 61, 2000
4. 60, 1994
5. 59, 2018

The 30-year moving average of 90° days has also been increasing. Since 2000, Denver has added an average of 9.5 such days to its annual figure. Since 1950, the annual average has increased by just over 90%.

Select statistics for the 30-year period ending in the specified years:

1950 23.3 days
1960 29.8 days
1970 29.8 days
1980 34.5 days
1990 33.8 days
2000 35.1 days
2010 37.8 days
2020 44.6 days

Since recordkeeping began in 1872, Denver has had 16 years during which there were 50 or more 90° readings. 11 (69%) have occurred during 2000 or later and 6 (38%) have occurred during 2010 or later.

The exceptional heat of summer 2020 and early September 2020 made this outcome possible. Denver's average high temperature during summer 2020 was 91.2°, which is the second highest figure on record. Such summers are likely to become more common in the years ahead with the average high temperature during summer likely to increase by nearly 1°F under the RCP 4.5 scenario by 2030 (and 2.9° from the 1981-2020 base figure).

[LibertyBell]

How does Denver, at over a mile in elevation, get so many more 90 degree days compared to NYC and even Philly?  

[donsutherland1]

1 hour ago, LibertyBell said:

How does Denver, at over a mile in elevation, get so many more 90 degree days compared to NYC and even Philly?  

Denver isn’t far from the Sonoran Desert. Heat can easily push through the Rockies and into the Northern Plains. There are no large water bodies to moderate the heat.

[skierinvermont]

2 hours ago, LibertyBell said:

How does Denver, at over a mile in elevation, get so many more 90 degree days compared to NYC and even Philly?  

All of what Don said plus because the air is dry I think it heats up faster during they day. We have pretty cool nights but it warms up quickly when the sun is out (which is almost every day in summer). The diurnal temperature range is a lot more than it is in NYC. Don't quote me on this but it makes sense.

[skierinvermont]

I think we would have hit 90 some other days as well if it weren't for the smoke. It was clearly holding temps down the last few days but most of the smoke cleared out today so we hit 90.

[LibertyBell]

13 hours ago, skierinvermont said:

All of what Don said plus because the air is dry I think it heats up faster during they day. We have pretty cool nights but it warms up quickly when the sun is out (which is almost every day in summer). The diurnal temperature range is a lot more than it is in NYC. Don't quote me on this but it makes sense.

That makes sense and is a reason why summer 2010 was much hotter than the summers that followed here, overperforming dry heat compared to high humidity heat.

 

[donsutherland1]

Denver reached 90 degrees today for a record 75th time this year. The 91-degree temperature beat the previous daily record of 89 degrees, which was set in 1992.

[LibertyBell]

12 hours ago, donsutherland1 said:

Denver reached 91 degrees today for a record 75th time this year. The previous daily record was 89 degrees, which was set in 1992.

Denver has my ideal climate, lots of temperature variations with some months where it can hit 100 and have snow!