Rockville, MD Climate

Climate Insight: Rockville, MD

The NOAA 1991–2020 climate normals describe Rockville, Maryland as a location with an annual average temperature of 56°F, ranging from a mean daily high of 65°F to a mean daily low of 47°F. July is typically the warmest month of the year, while January is the coldest. These thirty-year averages, computed from station USC00187705, smooth out year-to-year variability and give a baseline expectation for typical conditions in any given month.

Precipitation patterns matter as much as temperature for anyone planning to live, garden, or travel here. Rockville receives roughly 41.3 inches of precipitation each year, predominantly as rainfall. Growing-season length varies with elevation and microclimate, with the last spring freeze near April 1 and the first fall freeze near November 6. For energy use, 4,455 heating degree days and 1,279 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Rockville scores 77/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows — shoulder seasons for mild highs and lows, peak summer for July-driven heat, or deep winter for January-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.