Irwin, SC climate
Irwin has mild winters and warm summers. A typical July afternoon reaches 91°, a January night drops to 31°, and about 3 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Irwin feels like
Winter
Spring
Summer
Fall
Irwin 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 | 54° | 31° | 3.8" | 0.9" | 9 | 1 | 37° – 48° |
| February | 58° | 34° | 3.1" | 1.2" | 9 | 0 | 38° – 55° |
| March | 65° | 40° | 3.8" | 0.3" | 9 | 0 | 46° – 62° |
| April | 75° | 48° | 3.3" | 0 | 9 | 0 | 57° – 66° |
| May | 81° | 57° | 3.4" | 0 | 9 | 0 | 65° – 74° |
| June | 88° | 65° | 4.1" | 0 | 9 | 0 | 72° – 81° |
| July | 91° | 69° | 3.9" | 0 | 9 | 0 | 77° – 84° |
| August | 89° | 68° | 4.2" | 0 | 9 | 0 | 76° – 84° |
| September | 83° | 62° | 3.8" | 0 | 7 | 0 | 69° – 78° |
| October | 74° | 50° | 3.1" | 0 | 7 | 0 | 58° – 67° |
| November | 64° | 39° | 3.2" | 0 | 8 | 0 | 47° – 57° |
| December | 56° | 34° | 3.8" | 0.2" | 10 | 0 | 36° – 55° |
| Year | 73° | 50° | 43.5" | 2.6" | 103 | 2 |
“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 Irwin
Irwin gets 44 inches of rain and melted snow a year. August is the wettest month and October the driest. Rain or snow falls on about 103 days a year.
About 225 frost-free days a year
In half of years the last 32° night comes by March 27 and the first one by November 5. That leaves about 225 frost-free days for gardens, longer than 84% of U.S. towns.
Heating and cooling a home in Irwin
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Irwin, 61% of that work is heating and 39% 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 Irwin 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 Irwin averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.1°). The shift is smaller than in 75% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Irwin’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 Irwin’s climate
What is the coldest month in Irwin?
January, with a typical high of 54° and a low of 31°.
What is the hottest month in Irwin?
July, with a typical high of 91° and a low of 69°. About 56 days a year reach 90°.
How much snow does Irwin get?
About 3 inches in a normal winter, most of it in February.
When is the first frost in Irwin?
In half of years the first 32° night comes by November 5, and the last spring frost by March 27.
What is the rainiest month in Irwin?
August, with 4.2 inches of rain and melted snow. The year totals 44 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Irwin itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Catawba, SC (12 mi, snow) and Winthrop Univ, SC (21 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.