2000 Honda Civic Intermittent A/C

A/C will work fine and blow cold air during the morning or when it isnt very hot outside(85 degrees or so and below) When it has been sitting in the sun and the temp is 90 and above as it has been the last week or so the a/c will blow hot and will not get cold. The freon level is normal. Sometimes when driving down the road if the a/c is working it will go out and start to blow warm and give off a musty smell. Any ideas?

Thanks