second gear synchronizer is going bad, first signs are cold weather... and heck some manual transmissions do this with low miles so dont lose sleep over it.
You should just realize its going to do it and put it in neutral for a sec and let off the clutch then push the clutch back in and slide it into second gear after that until it warms up. My car is hard to get into second when its cold as well. You can change the fluid (supposed to do that regularly
its not a lifetime fluid) in the transmission~
do you speed shift hard into second? One other thing you can check is your clutch adjustment. If you have to have your foot actually pushing on the floor pushing in the clutch petal to shift then you have to much slack and not enough engagement (not pulling the cable enough with the clutch petal) and you need to adjust this. Basically you might be shifting the car with only X amount of clutch pushed in vs what you should have~ cold weather just accents such issues and makes them more noticeable. When I first purchased my car it was a pain how hard it was to shift, a clutch cable adjustment made it 10000x better.
You can adjust it by crawling down under the dash (facing down), looking above the accel petal and taking one hand and hold it on the clutch quadrant and the other and push the clutch petal down ease the clutch petal up and hold tension on the quadrant against its movement its trying to do. Let it slowly out and you will heard a "click" this is it taking up slack. Take up slack until the clutch petal is FIRM at the top (no flop) and test drive. Make sure you have a half inch of travel of the clutch petal as you push it in before the clutch slips (go 55mph or 45mph hold the gas constant with your foot and ease in on the clutch when the rpms jump thats slipping.)
If you have an after market quadrant you can use a firewall adjuster to do the something.