Northern Evia, about 130 kilometers (80 miles) northeast of Athens, suffered devastating fires over the summer, leaving the area more vulnerable to flash floods.
Storms battered the Greek capital and other parts of southern Greece, causing traffic disruption and some road closures.
The government issued push alerts in Greek and English to cellphones in affected areas, urging people to “avoid unnecessary movement and areas that have been or may be flooded.”
The weather is expected to improve Saturday.