Alright, I know its -10 or something here in indiana right now, but I am also talking about days when its 20-30 degrees outside as well. I am having problems with my 1999 civic si with just bolt on mods... for years its been like this.... i would say I start the car up 10-15 minutes before I leave for work... I drive 15-20 miles to work at about 10 miles its finally starting to warm up the temp gauge is reading right and the air blows out cold still.... when it warms up its nice warm air............ why does it take so long to warm up that is my question... all the controls work...

 

sounds like a thermostat stuck open. does the temp gauge ever get up to just about halfway? the temp should stay steady once the car reaches operating temp.

 

I just had to replace the thermostat on my 97 Civic for similar reasons. Pay a little extra and install an OEM replacement thermostat.

 

see I was going to start there with replacing it, but just didnt know if anyone had problems, it runs and has always ran a little tiny notch below the middle of the gauge but within the last few years (2yrs) it has been right below that notch lol thats hard to explain... and its way too cold to go take pictures.

 

Typically a thermostat issue. Get an OEM thermostat as recommended above. Good luck!