Aspen Novembers getting warmer |

Aspen Novembers getting warmer

Carolyn Sackariason
The Aspen Times
Aspen, CO Colorado

ASPEN – It’s getting warmer in Aspen – can’t you feel it?

Recent data from the city of Aspen show November’s high temperature at about 7 degrees warmer than the historic average.

In recent years, November in Aspen has been warming faster than any other month, according to city officials.

November temperatures have been warming at the rate of 6 degrees per decade for the high temperatures and 4 degrees per decade for the low temperatures.

“That is why scientists focus on longer-term trends to evaluate climate,” said Kim Peterson, Aspen’s global warming program manager, in a press release. “Short-term changes from month to month are much more variable.”

Support Local Journalism

This past November didn’t bring any days with below-zero temperatures, though December already has broken some records for its cold days and nights.

November’s temperatures concerned the Aspen Skiing Co. since the month is key for making snow.

The warmest November daytime average was in 2007, and the warmest nighttime average was in 2001, according to city officials.

Average temperatures in October are not warming as fast as they are in most months. October had nine days when it did not freeze overnight, and no days that topped 70 degrees.

Particulate air pollution levels (PM-10), on the other hand, were close to average for November. November is usually a month with low pollution levels because there aren’t as many cars on the road.

“Almost all PM-10 on high pollution days comes from traffic,” said Aspen Environmental Health Director Lee Cassin, in the press release.

Another factor keeping PM-10 levels down may have been the low precipitation.

“This November had the second-lowest precipitation of any November in the last 10 years, so streets would not have gotten as much sand and dirt tracked out as usual,” Cassin said.

The average PM-10 level in November was 18.4 millionths of a gram of PM-10 in each cubic meter of air. That’s compared to a federal standard of 50.

This past October’s air pollution levels were better than they were during the same period last year, and temperatures were cooler than average.

Average PM-10 levels this October were 11 millionths of a gram of pollution in every cubic meter of air, compared to 15 last October.

The drop could be because of weather, and lower traffic levels also likely contributed to the cleaner air.

PM-10 causes increases in illness and death rates from respiratory diseases, even at relatively low levels. The city of Aspen has several programs designed to reduce both PM-10 and greenhouse gas emissions.

For more information, visit For information on Aspen’s global warming programs, go to

Support Local Journalism