Glassmanor, MD climate
Glassmanor has chilly winters and warm summers. A typical July afternoon reaches 88°, a January night drops to 27°, and about 14 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Glassmanor feels like
Winter
Spring
Summer
Fall
Glassmanor 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 | 44° | 27° | 3.0" | 4.9" | 10 | 4 | 27° – 42° |
| February | 47° | 28° | 2.7" | 5.0" | 9 | 4 | 28° – 45° |
| March | 56° | 35° | 3.8" | 2.0" | 11 | 1 | 40° – 55° |
| April | 67° | 45° | 3.4" | 0 | 11 | 0 | 52° – 61° |
| May | 76° | 54° | 4.1" | 0 | 12 | 0 | 60° – 71° |
| June | 84° | 64° | 4.3" | 0 | 11 | 0 | 69° – 78° |
| July | 88° | 69° | 4.6" | 0 | 11 | 0 | 73° – 82° |
| August | 86° | 67° | 3.9" | 0 | 9 | 0 | 72° – 80° |
| September | 80° | 60° | 4.4" | 0 | 9 | 0 | 66° – 74° |
| October | 69° | 48° | 3.8" | 0 | 8 | 0 | 54° – 65° |
| November | 57° | 38° | 3.1" | 0.1" | 8 | 0 | 42° – 52° |
| December | 48° | 31° | 3.7" | 1.7" | 10 | 1 | 30° – 50° |
| Year | 67° | 47° | 44.9" | 13.7" | 118 | 10 |
“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 Glassmanor
Glassmanor gets 45 inches of rain and melted snow a year. July is the wettest month and February the driest. Rain or snow falls on about 118 days a year. Snow covers the ground about 10 days of the year.
About 217 frost-free days a year
In half of years the last 32° night comes by April 3 and the first one by November 8. That leaves about 217 frost-free days for gardens, longer than 81% of U.S. towns.
Heating and cooling a home in Glassmanor
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Glassmanor, 75% of that work is heating and 25% 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.
Glassmanor and its neighbors
Glassmanor borders 4 towns with climate data. January nights across them vary by 0.6°. Marlow Heights has the coldest January nights (26°) and Forest Heights the hottest July afternoons (89°). Glassmanor’s January low is 27° and its July high 88°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Glassmanor 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 Glassmanor averaged 1.7° warmer than the 1900s. The biggest change is in December (+2.8°). The shift is larger than in 81% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Glassmanor’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 30° to 50°. September is the most reliable, staying within 8°.
Common questions about Glassmanor’s climate
What is the coldest month in Glassmanor?
January, with a typical high of 44° and a low of 27°.
What is the hottest month in Glassmanor?
July, with a typical high of 88° and a low of 69°. About 38 days a year reach 90°.
How much snow does Glassmanor get?
About 14 inches in a normal winter, most of it in February.
When is the first frost in Glassmanor?
In half of years the first 32° night comes by November 8, and the last spring frost by April 3.
What is the rainiest month in Glassmanor?
July, with 4.6 inches of rain and melted snow. The year totals 45 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Glassmanor itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Washington Reagan Airport, VA (3 mi, snow) and Oxon Hill, MD (2 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.