Seneca, SC climate
Seneca has mild winters and warm summers, with plenty of rain. A typical July afternoon reaches 89°, a January night drops to 32°, and about 2 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Seneca feels like
Winter
Spring
Summer
Fall
Seneca 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 | 53° | 32° | 4.9" | 0.8" | 11 | 0 | 36° – 48° |
| February | 57° | 35° | 4.5" | 0.8" | 11 | 0 | 38° – 54° |
| March | 64° | 41° | 4.9" | 0.3" | 11 | 0 | 46° – 62° |
| April | 73° | 48° | 4.2" | 0 | 10 | 0 | 56° – 65° |
| May | 80° | 57° | 3.9" | 0 | 10 | 0 | 64° – 72° |
| June | 87° | 65° | 4.6" | 0 | 11 | 0 | 72° – 79° |
| July | 89° | 68° | 4.5" | 0 | 10 | 0 | 76° – 83° |
| August | 88° | 68° | 5.0" | 0 | 11 | 0 | 74° – 82° |
| September | 82° | 62° | 4.2" | 0 | 8 | 0 | 69° – 77° |
| October | 73° | 50° | 3.9" | 0 | 8 | 0 | 58° – 65° |
| November | 63° | 40° | 4.0" | 0 | 9 | 0 | 47° – 57° |
| December | 55° | 35° | 5.1" | 0.3" | 11 | 0 | 36° – 55° |
| Year | 72° | 50° | 53.7" | 2.2" | 120 | 1 |
“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 Seneca
Seneca gets 54 inches of rain and melted snow a year. December is the wettest month and October the driest. Rain or snow falls on about 120 days a year.
About 236 frost-free days a year
In half of years the last 32° night comes by March 21 and the first one by November 11. That leaves about 236 frost-free days for gardens, longer than 87% of U.S. towns.
Heating and cooling a home in Seneca
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Seneca, 64% of that work is heating and 36% 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.
How Seneca 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 Seneca averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.1°). The shift is smaller than in 79% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Seneca’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 36° to 55°. July is the most reliable, staying within 7°.
Common questions about Seneca’s climate
What is the coldest month in Seneca?
January, with a typical high of 53° and a low of 32°.
What is the hottest month in Seneca?
July, with a typical high of 89° and a low of 68°. About 53 days a year reach 90°.
How much snow does Seneca get?
About 2 inches in a normal winter, most of it in January.
When is the first frost in Seneca?
In half of years the first 32° night comes by November 11, and the last spring frost by March 21.
What is the rainiest month in Seneca?
December, with 5.1 inches of rain and melted snow. The year totals 54 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Seneca itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Clemson Univ, SC (8 mi, snow) and Clemson Oconee Co Airport, SC (5 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.