this data is misleading, it doesn't quantify the quality of the teams playing in the cold.
What was the Bears record over same period i warm games vs steelers record in warm games?
It is extremely misleading.
The recent Bears (since 1989) have had 17 losing seasons and 2 8-8 seasons.
The Pittsburgh Steelers (since 1970) have had 9 losing seasons and 5 8-8 seasons.
That means that since 1989, the Bears have had a winning season 36.67% of the time while the Steelers have had a winning season 71.4% of the time.
Notice how the winning seasons percentages and cold weather winning percentage are in the ballpark (though not expected to be accurate) for both teams?
If my math is right, they have won 209 games out of 480 since 1989 for a 43.5%. This just shows that they have been a poor team since 1989 and that is in cold weather, warm weather, hot weather, rainy weather, snowy weather and foggy weather.
It still does not show that the Bears are not a cold weather team (they might not be). Perhaps, they play teams much better in the cold, but because they are a poor team, they still end up losing.
Quickly looking at recent year December home games, there are trends to be seen.
2018 - beat Packers and Rams (Rams were a playoff team)
2017 - end of the end classic Fox. Lost to 49ers in a low scoring contest and destroyed the winless Browns
2016 - middle of the end classic Fox. Lost to Packers and Washington. Then again, they lost to almost everybody.
2015 - beginning of the end classic Fox. Lost to lions and Washington
2014 - 'Building the man' wheels feel off. Lost to Lions, Saints and Cowboys
2013 - 'Building the man' begins. Beat cowboys and lost to Packers.
2012 - Lovie's last stand. Lost to Packers and Seattle (while beating Vikings, Cards and Lions away. Must be nice to have easy teams away)
2011 - Lost to KC and Seattle and also lost away games to Oakland (when they were actually good, I believe), Denver and Packers
2010 - Beat Lions and Jets and lost to Patriots (who were obviously better than the Bears). Won Seattle and lost to Packers in playoffs.
The 2010 - 2012 seasons show why Lovie had to go. He never quite had an offense and his defense was getting old.
2013-2014 was what happens when a geek chooses the new coach because he is very similar to him. That shit got old quickly and there was a mutiny the 2nd year.
2015 - 2017 Fox. Nothing else needs to be said.
2018 Nagy looked really good his first year. He did not tinker with a growing and successful defense and gave Chicago a glimpse of a real offense. If the offense can take another step and the defense hold steady, those cold weather myths will become cold weather reality because the Bears will beat teams in cold weather, warm weather and any other weather they might come across.