The only way there can be five Sundays in February is if it is a leap year AND February 1 is a Sunday. The last time that happened was 2004, and the next times it will happen are 2032, 2060, 2088, and 2128.
Once every 28 years.
In 2032 there are 5 Sundays in February, May, August and October.
February, May, August and October.
january
There are always 4 Sundays in February, except if it is a leap year and the 1st of February is a Sunday. In that case there are 5 Sundays.
In 2001 there were five Sundays in April, July, September and December.
April, July, September and December have five Sundays in 2018.
The odds are exactly 14.5%, which makes the average frequency once per 6.9 years.
January, April, July, October and December in 2028 will have five Sundays.
March, June, August and November 2031 all have five Sundays.
January, April, July, October and December of 2017 have five Sundays each.
Four months will have five Sundays in 2022. They are January, May, July and October.