It's February and having dirt to ride is fantastic! Frozen trails are great to ride when they are completely frozen, but please get off those trails before they thaw. Sun hitting a frozen trail will melt it very quickly, and remember, you can encounter muddy trails even when it is below freezing outside.
Our local trails get a lot of use. Riding, running, or hiking them when they are muddy increases the damage to them by providing ruts for water to run in, enlarging puddles, and preventing drainage. As you may recall from a couple years ago, once dried, the ruts created during this early-season freeze/thaw cycle will remain for quite some time. They don't just smooth themselves out.
If you can see your tracks depressing into the ground, its too wet. If you encounter a puddle, go through it, not around it. Then, go ride some gravel instead!