Certified GKH Gardening Expert
It takes a little time, but with diligence you can get rid of most of them. I didn't see a location for you, but this time of year in the U.S. you can still add nitrogen one more time to your lawn. You can apply one of those that includes an herbicide for weeds.
Fall and spring are the times to apply a preemergent, which helps stop weeds from growing.
If you still have weeds in late spring, you can apply a postemergent to continue the eradication process.
Keeping the grass mowed will help prevent weeds from going to seed, and dropping them to lie in wait.
Also, proper mowing heights, watering and fertilizing will go a long way toward reducing the number of weeds that can grow. The healthier and thicker the lawn, the less weeds that can germinate.