Some businesses benefit (or suffer) more from seasonality than others. However, most companies, in one way or another, are impacted by seasonality. An icecream vendor, for one, will likely have a more challenging time selling ice cream during the wintertime due to reduced demand.
There are a couple of options to deal with this situation.
Option one. Either make all revenue during one or two seasons, so you can rest on your laurels for the remaining time. Not easy. It requires a strong brand and substantial financial buffer.
Option two. Apply aggressive marketing, among other initiatives, in an attempt to sell ice cream during the off-season.
Option three. Introduce new products (or services) that are better suited for the seasons where you typically see a decline in sales. Wafels could make an excellent addition. One that would likely sell more when the ice cream starts to sell less.
Don’t fight seasonality. Embrace it by making your business anti-cyclical.