Rockville has warm winters and warm summers, with plenty of rain
A typical July afternoon reaches 90°, a January night drops to 40°, and snow is almost unheard of.
A year in Rockville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Rockville’s climate
Read from where Rockville sits among South Carolina’s towns. The page puts what stands out first.
What a year in Rockville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Living with Rockville’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
284 frost-free days. The last frost comes by Mar 1 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Dec 6.
About 0.3" in a normal winter.
Months averaging under 55° run from December through February. Heating is 42% of the year’s heating-and-cooling load.
About 73 days a year reach 90°, and July afternoons average 90°.
The nicest months are February, March, April, May, October, November and December.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →Warmer than it used to be
The last 30 years in Rockville averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.5°).
A bigger shift than in 55% of U.S. towns.
Change by month
Rain and snow in Rockville
August is the wettest month and November the driest. Rain or snow falls on about 114 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
About 0.3" in a normal year, so most winters see none.
About 284 frost-free days a year
In half of years the last 32° night comes by March 1 and the first by December 6.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
How Rockville compares
Against every U.S. town on TownTapestry, each counted once, with its place in South Carolina.
Rockville 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 | 60° | 40° | 3.3" | 0.2" | 9 | 0 | 45° – 56° |
| February | 63° | 43° | 3.0" | 0.1" | 9 | 0 | 46° – 61° |
| March | 69° | 49° | 3.4" | 0 | 8 | 0 | 53° – 66° |
| April | 75° | 56° | 3.2" | 0 | 8 | 0 | 61° – 70° |
| May | 82° | 64° | 3.0" | 0 | 8 | 0 | 69° – 78° |
| June | 88° | 71° | 5.3" | 0 | 12 | 0 | 74° – 83° |
| July | 90° | 74° | 5.7" | 0 | 13 | 0 | 80° – 85° |
| August | 89° | 74° | 6.4" | 0 | 13 | 0 | 79° – 84° |
| September | 85° | 69° | 5.3" | 0 | 10 | 0 | 74° – 81° |
| October | 78° | 59° | 4.4" | 0 | 7 | 0 | 65° – 73° |
| November | 69° | 49° | 2.7" | 0 | 7 | 0 | 54° – 65° |
| December | 62° | 43° | 3.2" | 0 | 9 | 0 | 44° – 63° |
| Year | 76° | 58° | 48.7" | 0.3" | 114 | 0 |
Heating and cooling a home in Rockville
42% of the work is heating.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 44° to 63°. August is the most reliable, staying within 5°.
Common questions about Rockville’s climate
What is the coldest month in Rockville?
January, with a typical high of 60° and a low of 40°.
What is the hottest month in Rockville?
July, with a typical high of 90° and a low of 74°. About 73 days a year reach 90°.
How much snow does Rockville get?
Almost none. A normal year brings 0.3 inches.
When is the first frost in Rockville?
In half of years the first 32° night comes by December 6, and the last spring frost by March 1.
What is the rainiest month in Rockville?
August, with 6.4 inches of rain and melted snow. The year totals 49 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Rockville.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Rockville itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Charleston Intl Airport, SC (22 mi, snow) and Edisto Is Middleton Plantation, SC (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. Today’s forecast: National Weather Service.