Def. want to get your temps up. How did you start your charcoal and how much did you add? Do a search for Minion Method for the best way to fire up your WSM. If you didnt start Minion, may want to add some unlit charcoal to the ring and then 3/4 chimney of lit on top. A filled water pan can also cause your temps to be low.
Are you reading temps from the lid? They can usually report higher temps than the temps at the grate, but it's not usually significant.
Mark aka Earl
Slower Lower BBQ
(2) 22.5" WSM, (1) 18.5" WSM, (3) 22.5" Weber Kettles, Super Fast Red
Thermapen, Stoker, Airline Cart!