State regulators on Friday approved a rate hike for utilities Eversource and United Illuminating. The changes mean that if you’re a customer of those utilities, part of your bill will go up in January. The Public Utilities Regulatory Authority said the rate hike is tied to seasonal variations in the energy market. During the winter, prices for natural gas are higher, and since that fuel is used to generate most of the region’s wholesale power, “supply” portions of your bill go up. As a result of the change, come January 1st, Everource said the average residential customer can expect an increase of about $7 each month. UI said it’ll be about $5 per month. It’s worth nothing that these service rates traditionally decrease in the second half of the year. And PURA officials said winter rates approved for both UI and Eversource this time around are actually lower than others issued in the first half of the last three years. Still, rate hikes have been controversial. This summer, Eversource