Bastia Umbra is a municipality of 21 555 inhabitants (21/12/2020) in the province of Perugia in Umbria, located in the Valle Umbra, between Perugia and Assisi, along the Chiascio river.
The municipality of Bastia Umbra is the only one in Umbria that extends completely on a flat area in the northern part of the Valle Umbra, located about 200 m above sea level. The climate corresponds more closely to the characteristics of the central Tyrrhenian regions of Italy. The winters and autumns tend to be not too harsh, with frequent fog, especially in autumn and winter, and from the end of November to the beginning of March, extensive frost and night frosts are possible. The area has little snow thanks to the protection of the Apennine chain, although it is not unusual to see choreographic snowfalls. In autumn and spring there is the heaviest rainfall, which accompanies Atlantic disturbances or is preceded by a southerly breeze. Summers tend to be hot, sometimes sultry and with little rain. The rain that falls at this time of year is almost always linked to the phenomenon of the heat storm.
- – Average altitude: 200 m a.s.l.
- Maximum altitude: 215 m a.s.l.
- Minimum altitude: 180 m above sea level
- Climate classification: zone D, 1994 GG
Three watercourses flow through the territory of Bastia Umbra: the Chiascio river, the Tescio stream and the Cagnola ditch. The last two both flow into the Chiascio.