There are 30 days in June. June is the sixth month of the year and is preceded by May and followed by July. Both May and July have 31 days.
There are 12 months in a year: January, February, March, April, May, June, July, August, September, October, November and December. April, June, September and November each have 30 days. January, March, May, July, August, October and December each have 31 days. The month of February has 28 days in a normal year and 29 days in a leap year. The number of days in a month can be remembered by the "knuckle" method, where months falling on each knuckle have 31 days and each month in-between has 30 days.