I often get a question about spraying now for emerged weeds or waiting until we get rain and weeds are less stressed and perhaps easier to control. In my experience, weeds keep right on growing and in some cases can get too large for herbicides. I would spray even though it is dry. There may be a second or third flush of weeds if it rains over the next few weeks. Those will need to be dealt with using a second spray or by including a residual herbicide with the spray you are considering now.