Maine will need at least a foot of rain before the ground freezes to alleviate the monthslong drought that has been drying out all corners of the state.

If that amount of rain doesn’t arrive soon, drought conditions will likely linger into the spring.

The swath of Maine in extreme drought has expanded to cover nearly 34% of the state, according to U.S. Drought Monitor data released Thursday. The rest of the state is experiencing severe or moderate drought. The conditions have gripped much of Maine since the middle of August.

Some rain is on the way this week, forecasters say, but it won’t make a significant impact.

The National Weather Service estimates Maine would need 150% of its normal rainfall, or 6 to 12 inches, to end the drought before the ground freezes. Once soils freeze, precipitation can no longer effectively recharge aquifers, and drought conditions would persist until the snow melts in the spring.

That could create problems for people whose wells are running low — or have already dried up — because precipitation that would normally replenish groundwater won’t soak in.

“There won’t be enough groundwater for some people to get through the winter,” said Jon Palmer, a meteorologist with the National Weather Service office in Gray. “It’s definitely concerning.”

So far this year, 410 dry wells have been reported across Maine, according to the Maine Emergency Management Agency, which collects self-reported data from well owners through an online survey. That’s more than the past four years combined, according to state data.

The vast majority of newly dry wells are in southern Maine. Oxford County has seen at least 105 wells dry up, while 47 have been reported in Somerset County.

The drought has caused reductions in hay crops, shortened the season for many row crops, and could hurt next year’s berry and tree fruit harvests. Poland Spring has started scaling back withdrawals at multiple sights because of falling ground water levels.

The drought also created conditions that led fire officials to stop issuing burn permits. State officials said 747 wildfires burned a total of 473 acres by Oct. 2.

This year, Maine saw its sixth-driest summer on record, with nearly 3 fewer inches of rain than the historical average of 11 inches, according to the weather service.

Throughout May, snowmelt and wet conditions helped alleviate drought conditions that had lingered from the previous fall. That residual soil moisture helped make up for below-normal rainfall in June, according to a report from the Maine Drought Task Force.

But by July, southern Maine was seeing much less precipitation than normal. Above normal temperatures in August combined with very little rain created flash drought conditions.

Since then, drought conditions have spread and worsened.

Palmer, the weather service meteorologist, said the update released Thursday shows the extreme drought spread into a portion of eastern Franklin County but otherwise stayed largely the same as the previous week. That’s because temperatures have started to come down as Maine heads into the heart of fall.

“That’s good news, because warmer temps create a stronger need for precipitation,” Palmer said. “Really warm temps with no rain parches the soil. That’s why we ended up in with drought to start with.”

October and November are generally the wettest months of the year, with an average of 4 to 5 inches of rainfall each month, according to the weather service.

Much-needed rain is on the way this week, but Maine still faces a big hurdle before the ground starts freezing in November and December.

After a nice weekend, rain will move into Maine for Monday and Tuesday. The Portland area could see up to an inch of rain those days, then more later in the week, Palmer said.

“It will be enough rain to keep the status quo,” he said, “but not meaningfully improve drought conditions.”