November, December and January
Go nowDry, clear, and the volcanoes visible
The dry season at its best: clear skies, cool nights, and the volcanoes out rather than hidden in cloud, which is not guaranteed the rest of the year. This is when the Acatenango climb is most reliable. Christmas and New Year push prices up for two weeks; the rest is excellent and not especially crowded.
February and March
Go nowWarm, dry and still clear
Warmer than the turn of the year and still firmly dry, with good visibility and comfortable walking. Watch the calendar: Holy Week can fall in late March, and the weeks before it already fill up. Outside that, this is the most comfortable stretch of the year here.
April
Worth it, butHot, dry, and usually Holy Week
The hottest and driest month, with hazy skies from agricultural burning and the volcanoes often lost in it. Holy Week most often falls here, and when it does the town is full months in advance at several times the price. Extraordinary if that is why you came; difficult if it is not.
May and October
Worth it, butThe edges of the rains
May brings the first afternoon storms after months of dust, and the valley turns green within weeks. October is the reverse, with the rain easing and the landscape at its most vivid. Both mean clear mornings and a downpour after lunch, which is easy to plan around. Low prices, few people.
July and August
Worth it, butThe canícula, and northern holidays
A drier spell within the wet season, called the canícula, usually falls somewhere here — it is real but not guaranteed. Northern-hemisphere holidays raise prices despite it being green season, and the Spanish schools that Antigua is known for are at their fullest. Workable, and not the best value.
June and September
Think twiceThe wettest months, with the volcanoes in cloud
The heaviest rain of the year, with afternoons washed out and, more to the point, the volcanoes hidden in cloud for days at a time — which removes the view that defines this town. Trails turn to mud and the Acatenango climb becomes a gamble. Cheap and green, and the least reliable window.