There are 5 Sundays in January 2025. A quick way to determine the number of Sundays in any given month is to look at the first day of the month. If the first day of the month is a Sunday, then there will be 5 Sundays in that month. If the first day of the month is any other day of the week, then there will be 4 Sundays in that month.
January 2025 starts on a Wednesday, so there will be 4 Sundays in January 2025.