average temp in maryland in april
46.0Â°F. Baltimore's coldest month is January when the average temperature overnight is 23.5Â°F. In July, the warmest month, the average day time temperature rises to 87.2Â°F.The driest month in Baltimore is April with 3.00 inches of precipitation, and with 3.98 inches September is the wettest month.6.0Â°F. Baltimore's coldest month is January when the average temperature overnight is 23.5Â°F. In July, the warmest month, the average day time temperature rises to 87.2Â°F.