I live in a hot and humid climate (Tel Aviv), and usually I run at night. But some days I have plans in the evening, and my only chance to get a run in is by starting at around six, six-thirty (which in summer is about an hour before sunset).

How bad is this, in terms of exposure to the sun? I don't normally apply sunscreen for such runs. By the time I finish (about an hour) the sun is almost setting (or has set).

A final detail: let's say I do this about once a month. Is that below the threshold that I should be concerned about?