Too early to apply?

I'm all for getting a jump on things which is why I always recommend honing in on a prospective employer when selecting your clinical sites. That way you can essentially have a prolonged job interview during your rotation and remind them as often as possible without being a pest that you have every intention of joining their team after graduation. However if you are looking for a job with no inside connection it seems a bit early. You realistically won't be able to start work until probably July with verification, board exam and prescribing licenses. It might not be a bad idea to send an introductory inquiry but I'd make sure you aren't wasting too much of someone's time. A job that is open now and still open in July might be a red flag.