Happy Aphelion! Today marks the one day of the year Earth is farthest away from the sun. 94,500,000 miles to be exact. The difference between our closest and farthest points is around 3.1 million miles which is only about 3% of the total distance. So yes, there are times when we are closer and farther away from the sun in our orbit, but it's not a big enough difference for you to notice. The sun won't look smaller to us today than it does in January. 

You might be looking at the calendar asking yourself how we can be at our farthest point from the sun during our hottest season of the year. This positioning doesn't dictate our seasons; the tilt of the Earth does! When the north pole is tilted more toward the sun, the Northern Hemisphere is getting more insolation (incoming solar radiation) which creates our summer season. In our winter seasons, the south pole is what's tilted toward the sun.