Introduction Numerous studies described a link between weather phenomena and an increased incidence of cardiovascular and cerebrovascular events. We report a case of ocular decompression retinopathy with massive premacular haemorrhage secondary to acute intraocular pressure reduction in a patient with acute primary angle closure. At the time of admission, a change in weather conditions occurred with high temperatures and a strong Foehn wind known locally as halny. Case description A healthy 56-year-old man with acute primary angle closure who developed severe ocular decompression retinopathy with large prefoveal subhyaloid haemorrhage after pharmacological treatment was admitted to the hospital. The patient was elected for surgery and underwent vitrectomy with improvement of visual acuity to the baseline vision. Conclusions This report suggests that, in addition to an abrupt reduction in intraocular pressure as a causative factor, massive ocular decompression retinopathy may be significantly influenced also by environmental factors such as halny.