When it rains it pours:

many difficult things always happen at the same time

idiommeanings.com

Also delivered as, It never rains but it pours:

Good (or bad) things do not just happen a few at a time, but in large numbers all at once.

When it rains it pours:

many difficult things always happen at the same time

idiommeanings.com

Also delivered as, It never rains but it pours:

Good (or bad) things do not just happen a few at a time, but in large numbers all at once.

idioms.thefreedictionary.com

When it rains it pours, meaning: Troubles tend to pile up.

When it rains it pours:

many difficult things always happen at the same time

idiommeanings.com

Also delivered as, It never rains but it pours:

Good (or bad) things do not just happen a few at a time, but in large numbers all at once.