Baltimore lies in the humid subtropical climate in the Köppen climate classification, with long hot summers, cool to mild winters, and summer peak to annual precipitation.
Baltimore is part of USDA plant hardiness zones 7b and 8a.
Summers are normally hot, with occasional late day thunderstorms.
July the hottest month, has a mean temperature of 80.3 °F (26.8 °C).
Winters are chilly to mild but variable, with sporadic snowfall: January has a daily average of 35.8 °F (2.1 °C), though temperatures reach 50 °F (10 °C) rather often, but can drop below 20 °F (−7 °C) when Arctic air masses affect the area.

Spring and autumn are warm, with spring being the wettest season in terms of the number of precipitation days.
Summers are hot and humid with a daily average in July of 80.7 °F (27.1 °C), and the combination of heat and humidity leads to rather frequent thunderstorms.
A southeasterly bay breeze off the Chesapeake often occurs on summer afternoons when hot air rises over inland areas; prevailing winds from the southwest interacting with this breeze as well as the city proper's UHI can seriously exacerbate air quality.
In late summer and early autumn the track of hurricanes or their remnants may cause flooding in downtown Baltimore, despite the city being far removed from the typical coastal storm surge areas.

The average seasonal snowfall is 20.1 inches (51 cm), but it varies greatly depending on the winter, with some seasons seeing minimal snow while others see several major Nor'easters.
Due to lessened urban heat island (UHI) as compared to the city proper and distance from the moderating Chesapeake Bay, the outlying and inland parts of the Baltimore metro area are usually cooler, especially at night, than the city proper and the coastal towns.
Thus, in the northern and western suburbs, winter snowfall is more significant, and some areas average more than 30 in (76 cm) of snow per winter.
It is by no means uncommon for the rain-snow line to set up in the metro area.
Freezing rain and sleet occurs a few times each winter in the area, as warm air overrides cold air at the low to mid-levels of the atmosphere.
When the wind blows from the east, the cold air gets dammed against the mountains to the west and the result is freezing rain or sleet.

Extreme temperatures range from −7 °F (−22 °C) on February 9, 1934, and February 10, 1899, up to 108 °F (42 °C) on July 22, 2011.
On average, 100 °F (38 °C)+ temperatures occur on 0.9 days annually, 90 °F (32 °C)+ on 37 days, and there are 10 days where the high fails to reach the freezing mark.
Baltimore lies in the humid subtropical climate in the Köppen climate classification, with long hot summers, cool to mild winters, and summer peak to annual precipitation. Baltimore is part of USDA plant hardiness zones 7b and 8a. Summers are normally hot, with occasional late day thunderstorms. July the hottest month, has a mean temperature of 80.3 °F (26.8 °C). Winters are chilly to mild but variable, with sporadic snowfall: January has a daily average of 35.8 °F (2.1 °C), though temperatures reach 50 °F (10 °C) rather often, but can drop below 20 °F (−7 °C) when Arctic air masses affect the area.
Spring and autumn are warm, with spring being the wettest season in terms of the number of precipitation days. Summers are hot and humid with a daily average in July of 80.7 °F (27.1 °C), and the combination of heat and humidity leads to rather frequent thunderstorms. A southeasterly bay breeze off the Chesapeake often occurs on summer afternoons when hot air rises over inland areas; prevailing winds from the southwest interacting with this breeze as well as the city proper's UHI can seriously exacerbate air quality. In late summer and early autumn the track of hurricanes or their remnants may cause flooding in downtown Baltimore, despite the city being far removed from the typical coastal storm surge areas.
The average seasonal snowfall is 20.1 inches (51 cm), but it varies greatly depending on the winter, with some seasons seeing minimal snow while others see several major Nor'easters. Due to lessened urban heat island (UHI) as compared to the city proper and distance from the moderating Chesapeake Bay, the outlying and inland parts of the Baltimore metro area are usually cooler, especially at night, than the city proper and the coastal towns. Thus, in the northern and western suburbs, winter snowfall is more significant, and some areas average more than 30 in (76 cm) of snow per winter. It is by no means uncommon for the rain-snow line to set up in the metro area. Freezing rain and sleet occurs a few times each winter in the area, as warm air overrides cold air at the low to mid-levels of the atmosphere. When the wind blows from the east, the cold air gets dammed against the mountains to the west and the result is freezing rain or sleet.
Extreme temperatures range from −7 °F (−22 °C) on February 9, 1934, and February 10, 1899, up to 108 °F (42 °C) on July 22, 2011. On average, 100 °F (38 °C)+ temperatures occur on 0.9 days annually, 90 °F (32 °C)+ on 37 days, and there are 10 days where the high fails to reach the freezing mark.
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