Green Valley, MD climate
Green Valley has chilly, snowy winters and warm summers. A typical July afternoon reaches 86°, a January night drops to 24°, and about 31 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Green Valley feels like
Winter
Spring
Summer
Fall
Green Valley 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° | 3.1" | 9.4" | 10 | 8 | 23° – 40° |
| February | 44° | 26° | 2.7" | 11.1" | 10 | 9 | 24° – 44° |
| March | 53° | 32° | 4.0" | 4.8" | 10 | 3 | 37° – 53° |
| April | 65° | 42° | 3.6" | 0.2" | 11 | 0 | 49° – 59° |
| May | 74° | 51° | 4.3" | 0 | 11 | 0 | 58° – 69° |
| June | 81° | 60° | 4.4" | 0 | 11 | 0 | 67° – 75° |
| July | 86° | 65° | 4.5" | 0 | 10 | 0 | 70° – 79° |
| August | 83° | 63° | 3.5" | 0 | 10 | 0 | 69° – 76° |
| September | 77° | 56° | 4.6" | 0 | 9 | 0 | 63° – 71° |
| October | 66° | 45° | 3.8" | 0 | 9 | 0 | 52° – 62° |
| November | 54° | 36° | 3.2" | 0.8" | 8 | 1 | 38° – 50° |
| December | 44° | 28° | 3.6" | 5.1" | 10 | 5 | 27° – 47° |
| Year | 64° | 44° | 45.2" | 31.4" | 119 | 26 |
“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 Green Valley
Green Valley gets 45 inches of rain and melted snow a year. September is the wettest month and February the driest. Rain or snow falls on about 119 days a year. Snow covers the ground about 26 days of the year.
About 196 frost-free days a year
In half of years the last 32° night comes by April 14 and the first one by October 29. That leaves about 196 frost-free days for gardens, longer than 70% of U.S. towns.
Heating and cooling a home in Green Valley
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Green Valley, 83% of that work is heating and 17% is cooling, so the furnace matters far more than the air conditioner.
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.
How Green Valley 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 Green Valley averaged 1.6° warmer than the 1900s. The biggest change is in December (+2.8°). The shift is larger than in 76% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Green Valley’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 27° to 47°. August is the most reliable, staying within 7°.
Common questions about Green Valley’s climate
What is the coldest month in Green Valley?
January, with a typical high of 41° and a low of 24°.
What is the hottest month in Green Valley?
July, with a typical high of 86° and a low of 65°. About 13 days a year reach 90°.
How much snow does Green Valley get?
About 31 inches in a normal winter, most of it in February.
When is the first frost in Green Valley?
In half of years the first 32° night comes by October 29, and the last spring frost by April 14.
What is the rainiest month in Green Valley?
September, 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 Green Valley itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Damascus 3 Ssw, MD (5 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.