I had a trip to Guatemala planned for Dec 2015 and had to cancel at the last minute. Very sad.
I am going to have the first three weeks of August off and I am trying to decide where to go. I really want to revive my plans for Guatemala (Tikal/Lake Atitlan/Antigua), but the weather is a concern.
Any thoughts from frequent travelers to the region? I know you will not be able to predict the weather for me, but are washed out roads and/or all day rain common during that time?

Washed out roads and/or all day rain are always a possibility, but not great enough or common enough to change your plans. Bring a good raincoat and boots and you will be fine. I know....I live 15 km from Antigua.

The real weather disasters are the tail ends of hurricanes off the eastern shore; then we may get a lot of rain and washed out roads.

I'm usually in Guatemala during July and August and then once or twice more at different times during the year. In my experience in August the mornings are nearly always gloriously sunny. Sometimes it rains starting in the afternoon or evening, sometimes hard; even if the day seems sunny I carry a lightweight rain jacket with me. I think it's a wonderful time to visit. Enjoy!

Thanks, that is exactly what I wanted to hear! I just booked my ticket.