Dumbarton, VA climate
Dumbarton has chilly winters and warm summers. A typical July afternoon reaches 89°, a January night drops to 27°, and about 15 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Dumbarton feels like
Winter
Spring
Summer
Fall
Dumbarton 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 | 48° | 27° | 3.4" | 5.9" | 10 | 3 | 32° – 44° |
| February | 52° | 29° | 2.8" | 4.0" | 9 | 4 | 30° – 48° |
| March | 60° | 36° | 4.0" | 1.8" | 10 | 1 | 42° – 57° |
| April | 70° | 45° | 3.4" | 0 | 10 | 0 | 53° – 63° |
| May | 77° | 54° | 4.2" | 0 | 10 | 0 | 61° – 72° |
| June | 85° | 63° | 4.3" | 0 | 9 | 0 | 70° – 79° |
| July | 89° | 68° | 4.4" | 0 | 10 | 0 | 74° – 82° |
| August | 87° | 66° | 4.4" | 0 | 8 | 0 | 73° – 80° |
| September | 81° | 59° | 4.5" | 0 | 8 | 0 | 67° – 75° |
| October | 71° | 47° | 3.7" | 0 | 7 | 0 | 55° – 65° |
| November | 60° | 37° | 3.3" | 0 | 7 | 0 | 42° – 53° |
| December | 51° | 31° | 3.7" | 3.0" | 9 | 2 | 32° – 51° |
| Year | 69° | 47° | 46.2" | 14.7" | 106 | 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 Dumbarton
Dumbarton gets 46 inches of rain and melted snow a year. September is the wettest month and February the driest. Rain or snow falls on about 106 days a year. Snow covers the ground about 10 days of the year.
About 202 frost-free days a year
In half of years the last 32° night comes by April 10 and the first one by October 31. That leaves about 202 frost-free days for gardens, longer than 73% of U.S. towns.
Heating and cooling a home in Dumbarton
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Dumbarton, 74% of that work is heating and 26% 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.
Dumbarton and its neighbors
Dumbarton borders 2 towns with climate data. January nights across them vary by 0.3°. Laurel has the coldest January nights (27°) and Lakeside the hottest July afternoons (89°). Dumbarton’s January low is 27° and its July high 89°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Dumbarton 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 Dumbarton averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.1°). The shift is smaller than in 67% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Dumbarton’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 32° to 51°. August is the most reliable, staying within 7°.
Common questions about Dumbarton’s climate
What is the coldest month in Dumbarton?
January, with a typical high of 48° and a low of 27°.
What is the hottest month in Dumbarton?
July, with a typical high of 89° and a low of 68°. About 43 days a year reach 90°.
How much snow does Dumbarton get?
About 15 inches in a normal winter, most of it in January.
When is the first frost in Dumbarton?
In half of years the first 32° night comes by October 31, and the last spring frost by April 10.
What is the rainiest month in Dumbarton?
September, with 4.5 inches of rain and melted snow. The year totals 46 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Dumbarton itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Ashland, VA (10 mi, snow) and Ashland Hanover Co Municipal Airport, VA (8 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.