The best time to go is obviously in the summer, but January and February often have plenty of sun. August is fiesta season.
Fiesta Mayor
Huesca city has its Fiesta Mayor from 9 to 15 August, with concerts and public drunkenness, and you may wish to avoid this, or indeed make a point of going there. There are various international music festivals in the province in July and August.
Winter sports
In canfranc, benasque, astãºn, cerler, candanch㺠and other ski stations.
Canyoning
The descent of mountain rivers through caves and canyons, in wetsuits. dangerous in june due to flash floods.