In the sightseeing industry, weather means everything.

Thanks to Chicago’s bizarrely warm winter so far, the city’s sightseeing tours are having some of their best winter seasons in the history of their companies.

“We have been open for 18 years and I can tell you the weather on each of those days. That’s how important the weather is to our business,” said John Curran, the vice president of Chicago Trolley and Double Decker Co.

The hop-on hop-off trolley company doesn’t operate during inclement weather, meaning heavy snow and extreme cold. Curran said his company has been open every day this winter and was even open during Thursday's snowstorm.

He welcomed the unseasonable warmth. “December has had a very positive impact on our business,” Curran said. 

The Chicago Trolley and Double Decker Co. allows passengers to sit either inside the heated bus or on uncovered seats atop the bus. Curran said the latter are more desirable seats.

“It is an experience people seek out,” Curran said. “People want to ride upstairs, which makes our business very weather dependent.” 

Historically, the average December high in Chicago is 27 degrees, according to the National Weather Service. This December’s average high was 35 degrees, and one mid-December day even reached a high of 57 degrees.

Liz Johnson, the public relations consultant for Shoreline Sightseeing, said the unseasonably high temperatures have given the river cruise company its busiest winter ever.

“We have been open since 1939 and we have never been consistently running this late in the year,” Johnson said.  “We have run at least one day a week for the entire winter, which is unheard of.”

Shoreline Sightseeing usually ends its season after Thanksgiving and has one New Year’s Eve fireworks tour. But this year the company ran tours Thursday, Friday and Saturday of New Year’s weekend, according to Johnson.

Johnson said the unexpected boost in winter business has been tremendously helpful for the sightseeing company.

“We are in a business that typically has several months with no revenue,” Johnson said. “Even though we are usually closed for the winter, we still have administrative and sales staff to pay. This winter has been great for us.”

 This week the Chicago Convention and Tourism Bureau launched a $1.8 million television ad campaign aimed at bringing tourists to Chicago as the winter continues and temperatures inevitably drop, according to Crain’s Chicago Business. The ads will run in Illinois and neighboring Midwestern states during prime-time network and cable television stations.