^ Listen to your body - if you feel you wanna slow down, so slow down. If you feel you can run quicker, so run quicker. It is actually very healthy to run at different speeds. And of course, before you start running, perhaps try quick pacing first, depends on what you say by "shitty conditions.." also, it is very important to do 5 minute stretching before and after the running.

My second week - I felt I could run more, so I stretched the running to 5.5km in 40 mins (: next week it's gonna be even more.
Did I mention that I love seeing my progress in running?