A recent surge in migrant children from Central America across the U.S. border has eased, but the numbers are still high compared to historical standards, and could rise again once the weather cools down, the White House said on Friday.

“Historical trends also indicate that as the weather cools and as we enter the fall and winter season, traditionally the rates of apprehension – the rates of those who attempt to illegally enter the country – go back up,” White House spokesman Josh Earnest told reporters.