What temperatures can I expect in Baltimore City throughout the year?

Baltimore City averages 75°F in summer (June–August), 35°F in winter (December–February), and moderate temperatures in spring and fall. Summer heat often exceeds 85°F on 20–30 days annually, while winter lows dip below freezing on roughly 100 days per year. Spring and fall typically range from 50°F to 65°F. The National Weather Service Baltimore/Washington office issues daily forecasts and seasonal outlooks specific to Baltimore City.

Monthly breakdown

Summer (June–August) brings the warmest conditions. Average highs reach 85–88°F, though heat waves can push readings into the low 90s. Humidity is notably high during July and August, often making the air feel 5–10 degrees warmer than the actual temperature. The summer of 2023 recorded multiple days above 95°F, illustrating the variability within the season.

Fall (September–November) cools gradually from the summer peak. September averages 78°F, October settles around 60°F, and November drops to 48°F. This season is generally drier and less humid than summer, making it a preferred time for outdoor activity in the city.

Winter (December–February) is the coldest period. Average highs hover around 43°F, with lows near 32°F. Snow is inconsistent; Baltimore City receives an average of 9–10 inches per winter, though this varies sharply year to year. In some years, measurable snow may fall only once or twice; in others, multiple storms bring 20+ inches total. Below-zero temperatures occur occasionally but are not typical.

Spring (March–May) transitions from cold to warm unevenly. March often still feels wintry, with highs around 50°F and occasional snow. April warms rapidly to the mid-60s, and May reaches 75°F. This season also brings the most unpredictable weather, with warm days sometimes followed by sudden cold snaps.

Humidity and "feels like" temperature

Baltimore's waterfront location along the Patapsco River and proximity to the Chesapeake Bay create persistent humidity, especially May through September. Summer dew points commonly reach 65–70°F, which raises the "heat index" (what the temperature feels like) noticeably above the actual air temperature. On a 90°F day with high humidity, the heat index can reach 100°F or higher. This matters for planning outdoor events, exercise, or time spent in non-air-conditioned spaces downtown or along the Inner Harbor.

Frost and freeze dates

The last spring frost in Baltimore City typically occurs around May 5, and the first fall frost arrives around October 10. These dates matter for gardeners and landscapers planning plantings in Baltimore neighborhoods. The frost-free growing season lasts roughly 158 days, shorter than southern Maryland but longer than northern Pennsylvania.

Where to find current and forecast data

The National Weather Service Baltimore/Washington field office (responsible for Baltimore City) issues forecasts at weather.gov. This is the authoritative source for warnings, advisory alerts, and hourly updates. Weather Underground, AccuWeather, and other commercial services also cover Baltimore City but rely partly on NWS data.

For historical climate data, the NOAA National Centers for Environmental Information publishes 30-year climate normals (averages calculated from 1991–2020 data). These normals are updated every ten years and provide the baseline figures cited in this article. The Baltimore-Washington International (BWI) Airport maintains long-term weather records that are publicly accessible through NOAA's climate database.

Indoor comfort planning

Winter heating and summer air conditioning are both essential in Baltimore. Winter heating typically runs November through March, and air conditioning is standard from May through September. The transitional months (April and October) often require neither system on many days, though weather swings can demand both within the same week. Visitors should pack layers and check forecasts before arrival.

Severe weather considerations

Baltimore experiences occasional severe thunderstorms in spring and summer, particularly from April through June when warm, moist air collides with cold fronts. The National Weather Service issues severe thunderstorm watches and warnings when conditions favor damaging winds, hail, or tornadoes. Tropical systems occasionally affect Baltimore in late summer and fall, bringing heavy rain and wind; Hurricane Isabel (2003) is a historical reference point for the region's hurricane risk. Winter nor'easters can produce heavy snow or coastal impacts, particularly along the Chesapeake Bay shoreline within city limits (Canton, Fells Point, Harbor East).