HELENA - A drop in market prices for natural gas and electricity is enabling NorthWestern Energy to reduce its rates for both commodities Feb. 1, including a 12.5 percent cut in natural gas rates for homeowners.

Rates for NorthWestern’s 310,000 electricity customers in Montana also will be declining about 4.5 percent in February — although those rates will remain the highest in the region among major utilities.

John Hines, director of energy supply for NorthWestern, said the reductions are tied to a “softening’’ of market prices for natural gas, which has fallen off nationwide in response to warmer-than-usual winter weather.

“If the national natural gas market continues to be soft the last couple of months of the heating season, we’ll hopefully (continue) to see these kind of prices,’’ he said Thursday.

The reduction is “good timing for Montana consumers, given that we’re still in the winter heating season,’’ Hines added.

NorthWestern, which serves 160,000 natural gas customers in Montana, usually makes monthly changes in rates for both electricity and gas, reflecting changes in the market.

The utility does not own any power plants or natural gas wells, and therefore must buy all its energy for customers on the wholesale market.

As energy prices have hit record highs the past six months, NorthWestern customers have been on a roller-coaster ride of changing electric and natural gas rates. Here’s a closer look at upcoming changes for each set of rates:

n On natural gas, NorthWestern residential customers will be paying $12.05 per dekatherm starting in February. That’s down from the current rate of $13.78 per dekatherm, a 12.5 percent reduction.

Residential customers consume an average of 10 dekatherms per month, but that amount is usually higher in the winter.

A monthly bill at 10 dekatherms will drop from $144 down to $127. This bill includes a monthly service charge of $6.54.

While the February price is a substantial reduction, it’s still 35 percent higher than rates paid last summer.

n On electricity, NorthWestern residential customers will pay about 8.43 cents per kilowatt hour (kWh) beginning in February. The current rate is about 8.83 cents per kWh.

NorthWestern says its average homeowner customer consumes 750 kWh per month. A monthly bill at this level of consumption will drop from about $71 this month to $68 next month, or slightly more than 4 percent. The monthly bill for electricity also includes a $4.78 service charge.

NorthWestern’s service area includes most of western and central Montana and parts of eastern Montana.

Montana-Dakota Utilities provides natural gas to 73,000 eastern Montana customers, including Billings, and electricity to about 24,000 customers in extreme eastern Montana.

MDU’s gas rates have been lower than NorthWestern’s rates this month, but new MDU rates for February weren’t available Thursday. MDU also adjusts its gas rates monthly, depending on market prices.

Electric rates for MDU customers have been unchanged for several years, because it remains a fully regulated utility for electricity.