We spent a few days camped next to Iglesia Mary Auxilidora, a gem of church in Cartago at the base of Volcan Irazu. (Note the climate data on Cartago’s Wikipedia page.)
While in Cartago we made an aborted attempt to get to the crater at Volcan Irazu. The fog was just too heavy. We moved to Lago de Cachi, a man-made reservoir that feeds a hydroelectric plant. When we were leaving we noticed two things: Volcan Turrialba was erupting and the sky was cloud free. We changed our plans and went to Volcan Irazu. It’s not every day that you can walk across a volcanic crater and see the ash cloud from another volcano.