Budget pressure is normal every year, not a one-time event: wage costs, snow removal, road repair and utility upgrades all rise, and council balances that against the tax base measured on 80 percent of assessed value under the province's residential percentage of value, not the full assessed figure.
If you are trying to track what is actually proposed for the coming year, the source is the City of Saskatoon's own budget documents and council meeting record, published well before the mill rate is finalized, not a figure that surfaces without a stated source.
For a seller, what matters is how the finalized mill rate affects holding costs during your listing window, which your realtor can factor into timing. Get your hand-reviewed valuation from Joel Dyck.