Boulder Halloween revelers and trick-or-treaters didn't see any rain or snow, but their celebration was haunted by chilly temperatures and gusting winds late into the evening.

The National Weather Service issued a high wind warning just before 9 p.m., effective until 6 a.m. Friday. It cautioned of westerly winds blowing at 40 to 60 mph, with gusts as high as 80 mph possible in the foothills and wind-prone areas such as Colo. 93, between Boulder and Golden.

That exceeds the minimum windspeed of hurricanes, which have windspeeds of 75 mph or more.

"We don't think it will last long, though. They should start to diminish by 3 a.m. or so," said NWS meteorologist Kyle Fredin.

Wind gusts of 64 mph and 73 mph had already been recorded at the National Wind Technology Center and at NCAR.

Boulder police responded earlier in the evening to reports of wind-blown trees sparking power lines on 15th Street just north of Arapahoe Avenue, but no fire was reported.

The overnight low is expected to be in the mid-30s.

Friday's forecast calls for sunny skies with a high of 50 to 56 and still breezy, with northwesterly winds of 10 to 15 mph into the aftenoon. The overnight low Friday is expected to be near 32.

Saturday's forecast is for sunny skies with a high in the low to mid-60s.

"It will be more of the same Sunday," Fredin said.

The weather will take a turn for the worse Monday, Fredin said, with rain mixing with snow in the afternoon, changing completely over to snow Monday night. Accumulation totals for Monday night are uncertain, Fredin said. Lows Monday night could sink into the low 20s.