Grandma's Marathon weekend is upon us, and both runners and spectators from around the world are prepared to descend on the Twin Ports for one of the area's biggest annual events. What can runners and fans expect the weather to do for race weekend? Here's the latest forecast.

Friday

William A. Irvin 5K (6:00 pm - Downtown Duluth)

Mostly cloudy and 52 degrees with a breeze out of the east-northeast at 12 mph.

Live Entertainment (7:00 pm - 1:00 am - Entertainment Tents in Canal Park, Duluth)

Partly to mostly cloudy, with temperatures falling to around 46 degrees accompanied by a 5-10 mph east-northeast breeze and a stray shower or thunderstorm is a possibility.

Saturday

Morning Forecast (Starting Line - Two Harbors)

Partly to mostly cloudy with fog possible and a slight chance of a rain shower.. Temperature at race start time will be 47 degrees, and a lake breeze (east-northeast) of 5-10 mph will carry through the course. Humidity levels will be high, around 90%.

Morning Forecast (Finish Line - Canal Park, Duluth)

Partly to mostly cloudy conditions and a 10% chance of rain showers are possible at the start time of the race. Temperatures will be around 46 degrees with a east-northeast breeze off the lake at 5-10 mph. Fog is possible around race start time. Humidity will be around 90%.

Daytime Forecast (Canal Park, Duluth)

Partly to mostly cloudy with a high temperature of 57 through the afternoon. A primarily east breeze 5-10 mph through the afternoon and into the evening. Rain chances are minimal during the day.

Evening Forecast - Entertainment Tents (Canal Park, Duluth)

Slight chance of rain showers through the evening (particularly late in the evening) as partly to mostly cloudy conditions hang around. Temperatures will land around 47 degrees in the evening with a northeast breeze of 5-10 mph.