Garrison, MD climate
Garrison has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 87°, a January night drops to 24°, and about 19 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Garrison feels like
Winter
Spring
Summer
Fall
Garrison weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 41° | 24° | 3.2" | 6.4" | 10 | 4 | 24° – 40° |
| February | 45° | 25° | 2.9" | 7.5" | 9 | 5 | 24° – 43° |
| March | 53° | 32° | 4.0" | 2.8" | 11 | 2 | 37° – 52° |
| April | 66° | 42° | 3.8" | 0 | 11 | 0 | 50° – 59° |
| May | 75° | 52° | 4.4" | 0 | 12 | 0 | 59° – 69° |
| June | 83° | 61° | 4.4" | 0 | 11 | 0 | 68° – 76° |
| July | 87° | 66° | 4.6" | 0 | 10 | 0 | 71° – 80° |
| August | 85° | 64° | 4.2" | 0 | 10 | 0 | 70° – 77° |
| September | 78° | 57° | 4.7" | 0 | 9 | 0 | 64° – 71° |
| October | 67° | 45° | 4.4" | 0 | 9 | 0 | 53° – 62° |
| November | 55° | 35° | 3.7" | 0.1" | 9 | 0 | 39° – 50° |
| December | 46° | 28° | 3.8" | 2.5" | 10 | 2 | 28° – 48° |
| Year | 65° | 44° | 48.0" | 19.3" | 121 | 13 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Garrison
Garrison gets 48 inches of rain and melted snow a year. September is the wettest month and February the driest. Rain or snow falls on about 121 days a year. Snow covers the ground about 13 days of the year.
About 220 frost-free days a year
In half of years the last 32° night comes by April 2 and the first one by November 7. That leaves about 220 frost-free days for gardens, longer than 82% of U.S. towns.
Heating and cooling a home in Garrison
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Garrison, 78% of that work is heating and 22% is cooling.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Garrison and its neighbors
Garrison borders 3 towns with climate data. January nights across them vary by 0.3°. Owings Mills has the coldest January nights (24°) and Pikesville the hottest July afternoons (88°). Garrison’s January low is 24° and its July high 87°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Garrison compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Garrison averaged 1.9° warmer than the 1900s. The biggest change is in December (+3.0°). The shift is larger than in 92% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Garrison’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 28° to 48°. September is the most reliable, staying within 7°.
Common questions about Garrison’s climate
What is the coldest month in Garrison?
January, with a typical high of 41° and a low of 24°.
What is the hottest month in Garrison?
July, with a typical high of 87° and a low of 66°. About 18 days a year reach 90°.
How much snow does Garrison get?
About 19 inches in a normal winter, most of it in February.
When is the first frost in Garrison?
In half of years the first 32° night comes by November 7, and the last spring frost by April 2.
What is the rainiest month in Garrison?
September, with 4.7 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Garrison itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Baltimore Wash Intl Airport, MD (17 mi, snow) and Cylburn, MD (6 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.