WESTPORT — The prospect of rain over the next several days is good news.

Though southwestern Connecticut has basked in a stretch of sunny, dry days over the last several weeks, conditions now pose a “very high” risk of fire, town Fire Marshal Terrence Dunn warns in a statement posted Tuesday on the Fire Department’s Facebook page.

That prompted Dunn to issue an “immediate” ban on open burning in town until further notice.

“The fire danger level is very high in our area,” Dunn said. “Fires will spread rapidly and quickly increase in intensity right after ignition.”

The ban on open burning means:

• All outdoor burning is prohibited, including bonfires, campfires and brush burning.

• Using grills and small, contained cooking devices is allowed, but residents are urged to exercise extreme caution.

• People should be especially vigilant to prevent accidental ignition, including discarding cigarettes or operating machinery that could spark a fire.

Relief, however, may be on the way.

There is a chance of rain later Wednesday and a higher likelihood of rain and thunderstorms Thursday afternoon and evening, according to the National Weather Service.

Both days are expected to be mostly cloudy, according to the weather service, with high temperatures in the upper 60s Wednesday and mid-70s Thursday.