I am about to start my internship year. All else equal (special dates like weddings, family issues), when would be the best time to take vacation (considering the "intern blues", fatigue, weather, etc.)?
It doesn't really matter when you take it. The three things I'd avoid are:
1) Taking ALL of your year's vacation during the
first month -- rare that they'd let anyone do it unless absolutely necessary, i.e. pregnant and due date is in July,
2) Taking ALL of your year's vacation during the last month -- too little break throughout the year, and again I wouldn't do it unless absolutely necessary, i.e. pregnant and due date is in June,
3) Taking vacation too early, such as in July or August before you can really appreciate it!
Months when you are more tired are, as above, January and February. You can take vacation at that time. Or, I took mine in March and whew, I was happy to celebrate finishing February by then!
Take your vacation any time, otherwise.