A congressional recess is a time when congress isn’t meeting but will meet again. The recesses usually fall around a major holiday (usually lasting a week or two) and the month of August. Check your current year’s calendar for exact dates of recesses:
Presidents Day: February
Passover/Easter: March or April
Memorial Day: Last week of May
Independence Day: First week of July
August: Full month until Labor Day in September
First Thursday in October: Target adjournment