A weak low pressure system is expected to spread cold, gusty winds across most of San Diego County Monday and could generate light rain in the mountains, which could make driving dicey east of Alpine, the National Weather Service said. Forecasters said the daytime high in San Diego should top out at 67 on Monday, 65 on Tuesday and 66 on Wednesday. The seasonal high is 74. The average monthly temperature has been running 1.2 degrees below average, and the city hasn’t received appreciable rain. San Diego averages 0.39 inches of precipitation during the first three and a half weeks of October. Forecasters say the wind will arrive out of the northwest and will blow hardest in East County, gusting 40 mph to 45 mph in some areas and hitting 60 mph to 65 mph on Interstate 8 near the border of San Diego and Imperial counties. Gusts in the 20 mph to 23 mph range are possible along the coast, where the surf will reach upwards of 4 feet. The weather will warm a bit on Thursday, which is Halloween. Temperatures will drop quickly after sunset, falling to 54 in San Diego, 51 in Borrego Springs, 48 in San Marcos, 47 in Escondido and El Cajon, and 40 in Julian.