Blackpool has, like all of the UK, a temperate maritime weather, translating to a limited annual temperature range, rainfall throughout the year, and high wind levels.
Summers: June, July August are summer months with occasional thunderstorms and heat-waves. Most days in summer are warm, but evenings can be cool. The summers are pleasant on clear days. During a normal summer, the warmest day will likely average 28 degree Celsius, with slightly fewer than 5 days a year attaining a temperature of 25 degree Celsius or above.
Autumn: September, October, November is autumn season and the weather is pleasant and mild which makes it a good season to visit this place.
Winter: December to February is winter season with January being the coldest month. Winter means about 6 to 7 hours of daylight in total.
Spring: March to May is spring season and known for pleasant weather. Spring is also a high season to visit Blackpool, be it with your family or with the love of your life.
So, the best time to visit Blackpool would ideally be during these summer months (between April to July) and spring (between March to May), as the heat is quite bearable and the rains are less likely to occur.