Photo: Ser Amantio di Nicolao · CC BY-SA 4.0South Run’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 88°, a January night drops to 27°, and about 13 inches of snow falls in a normal winter.
A year in South Run at a glance
Each month’s typical high and low, and what it brings.
What stands out about South Run’s climate
Compared with towns across the U.S., with South Run’s place in Virginia beside it.
What a year in South Run feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 202 frost-free days a year
In half of years the last 32° night comes by April 9 and the first by October 31. Day counts come from NOAA’s station at Vienna, VA, 10 miles from the town’s center, 110 ft higher; frost dates and degree days from Dalecarlia Reservoir, MD, 16 miles away.
The 2023 USDA map puts South Run’s center in zone 7b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 6°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 13 inches of snow a winter
Snow, measured at Franconia 1.3 Sse, VA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 43 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 116 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in South Run
77% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Dalecarlia Reservoir, MD.
Living with South Run’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
202 frost-free days in zone 7b. The last frost comes by Apr 9 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 31.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 8.3 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in South Run from natural hazards, river flooding is the largest share (79%); heat waves, cold waves, winter storms and ice storms together are 7%. Normals are averages; the hazards page covers the extremes.
Natural hazards →South Run and its neighbors
Every town next door is within a degree of South Run in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like South Run’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| South Run, VA | 27° | 88° | 43" | 13" |
| Hurricane, WV | 25° | 87° | 44" | 11" |
| Chester, IL | 24° | 88° | 44" | 12" |
| St. Louis, MO | 24° | 88° | 42" | 14" |
| Johnson City, TN | 27° | 87° | 46" | 9.2" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in South Run averaged 1.7° warmer than the 1900s. The biggest change is in December (+2.8°).
A bigger shift than in 75% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How South Run compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with South Run’s place among Virginia’s.
South Run weather by month
Highs, lows and precipitation from NOAA’s grid at South Run’s center; snow, wet days and snow on the ground from Franconia 1.3 Sse, VA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 44° | 27° | 2.9" | 4.8" | 10 | 4 | 27° – 42° |
| February | 47° | 28° | 2.6" | 3.5" | 9 | 5 | 27° – 45° |
| March | 56° | 35° | 3.5" | 2.8" | 9 | 2 | 40° – 55° |
| April | 67° | 45° | 3.3" | 0.0" | 11 | 0 | 52° – 61° |
| May | 75° | 54° | 4.1" | 0.0" | 12 | 0 | 60° – 70° |
| June | 83° | 63° | 4.1" | 0.0" | 11 | 0 | 69° – 78° |
| July | 88° | 68° | 4.4" | 0.0" | 9 | 0 | 73° – 82° |
| August | 86° | 66° | 3.7" | 0.0" | 10 | 0 | 71° – 80° |
| September | 79° | 59° | 4.3" | 0.0" | 8 | 0 | 66° – 74° |
| October | 68° | 47° | 3.6" | 0.0" | 9 | 0 | 53° – 64° |
| November | 57° | 37° | 3.0" | 0.1" | 8 | 0 | 41° – 53° |
| December | 48° | 31° | 3.5" | 2.2" | 10 | 1 | 30° – 50° |
| Year | 66° | 47° | 42.9" | 13.4" | 116 | 12 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 30° to 50°. September is the most reliable, staying within 8°.
Where South Run’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at South Run’s center.
- Snow: Franconia 1.3 Sse, VA.
- Frost dates, heating and cooling: Dalecarlia Reservoir, MD, 16 miles away.
- Freezing nights, 90° and 100° days: Vienna, VA, 10 miles from the town’s center, 110 ft higher; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about South Run’s climate
What is the weather like in South Run?
A typical July afternoon reaches 88°, a January night drops to 27°, and about 13 inches of snow falls in a normal winter. Milder January nights than 67% of U.S. towns; hotter July afternoons than 66% of U.S. towns.
How cold does it get in South Run in winter?
January nights average 27°. About 99 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 27°.
How much snow does South Run get?
About 13 inches in a normal winter at Franconia 1.3 Sse, VA, most of it in January, with snow on the ground about 12 days a year.
How hot does it get in South Run?
July, with a typical high of 88° and a low of 68°. About 13 days a year reach 90° (Dalecarlia Reservoir, MD).
When is the first and last frost in South Run?
In half of years the last spring frost (32°) comes by April 9 and the first fall frost by October 31, about 202 frost-free days, at Dalecarlia Reservoir, MD.
What growing zone is South Run in?
Zone 7b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 6°.
What is the best time of year to visit South Run?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is South Run getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 75% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in South Run.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.