Johnston weather by month
What a typical year looks like in Johnston, South Carolina: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Saluda, 18 km from Johnston; records cover 1902–2026.
The year at a glance
- Precipitation a year
- 46.8 in1189 mm
- Snow a year
- 0.4 in1 cm
- Last spring freeze
- Mar 29
- First fall freeze
- Nov 1
- Heating degree days
- 2,954
- Cooling degree days
- 1,969
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 17°−8° (heating, 99%) and 100°38° (cooling, 1%).
Month by month
Johnston in January
Highs average 54°12° and lows 32°0°, with 4.1 in104 mm of precipitation in a typical January.
- Record high
- 83°28° (1944)
- Record low
- −2°−19° (1985)
- Heating degree days
- 688
- Cooling degree days
- 0
Johnston in February
Highs average 59°15° and lows 34°1°, with 3.8 in97 mm of precipitation in a typical February.
- Record high
- 84°29° (2026)
- Record low
- 7°−14° (1917)
- Heating degree days
- 524
- Cooling degree days
- 1
Johnston in March
Highs average 66°19° and lows 40°5°, with 4.6 in116 mm of precipitation and 0.2 in0.5 cm of snow in a typical March.
- Record high
- 92°33° (1907)
- Record low
- 5°−15° (1980)
- Heating degree days
- 374
- Cooling degree days
- 12
Johnston in April
Highs average 75°24° and lows 48°9°, with 3.1 in78 mm of precipitation in a typical April.
- Record high
- 98°37° (1914)
- Record low
- 21°−6° (1907)
- Heating degree days
- 153
- Cooling degree days
- 59
Johnston in May
Highs average 83°28° and lows 58°14°, with 3.5 in89 mm of precipitation in a typical May.
- Record high
- 103°39° (1941)
- Record low
- 32°0° (1971)
- Heating degree days
- 31
- Cooling degree days
- 196
Johnston in June
Highs average 89°32° and lows 67°19°, with 4.2 in106 mm of precipitation in a typical June.
- Record high
- 109°43° (2012)
- Record low
- 43°6° (1976)
- Heating degree days
- 1
- Cooling degree days
- 388
Johnston in July
Highs average 93°34° and lows 70°21°, with 4.3 in109 mm of precipitation in a typical July.
- Record high
- 109°43° (1980)
- Record low
- 50°10° (1947)
- Heating degree days
- 0
- Cooling degree days
- 508
Johnston in August
Highs average 91°33° and lows 69°21°, with 4.5 in114 mm of precipitation in a typical August.
- Record high
- 108°42° (1925)
- Record low
- 50°10° (1912)
- Heating degree days
- 0
- Cooling degree days
- 462
Johnston in September
Highs average 85°30° and lows 62°17°, with 4 in101 mm of precipitation in a typical September.
- Record high
- 109°43° (1912)
- Record low
- 35°2° (1967)
- Heating degree days
- 10
- Cooling degree days
- 272
Johnston in OctoberThis month
Highs average 75°24° and lows 50°10°, with 3.2 in82 mm of precipitation in a typical October.
- Record high
- 101°38° (1954)
- Record low
- 21°−6° (1952)
- Heating degree days
- 142
- Cooling degree days
- 62
Johnston in November
Highs average 64°18° and lows 39°4°, with 3.4 in85 mm of precipitation and 0.1 in0.3 cm of snow in a typical November.
- Record high
- 92°33° (1961)
- Record low
- 12°−11° (1950)
- Heating degree days
- 411
- Cooling degree days
- 7
Johnston in December
Highs average 56°13° and lows 34°1°, with 4.3 in108 mm of precipitation and 0.1 in0.3 cm of snow in a typical December.
- Record high
- 81°27° (1931)
- Record low
- 1°−17° (1962)
- Heating degree days
- 620
- Cooling degree days
- 2