Ketchum weather by month
What a typical year looks like in Ketchum, Idaho: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Ketchum Ranger Station, 1 km from Ketchum; records cover 1937–2026.
The year at a glance
- Precipitation a year
- 17.3 in440 mm
- Snow a year
- 102 in259 cm
- Last spring freeze
- Jun 20
- First fall freeze
- Sep 2
- Heating degree days
- 9,069
- Cooling degree days
- 63
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −8°−22° (heating, 99%) and 89°32° (cooling, 1%).
Month by month
Ketchum in January
Highs average 31°0° and lows 8°−13°, with 2.3 in57 mm of precipitation and 27 in69 cm of snow in a typical January.
- Record high
- 54°12° (2015)
- Record low
- −42°−41° (1943)
- Heating degree days
- 1406
- Cooling degree days
- 0
Ketchum in February
Highs average 35°2° and lows 11°−12°, with 1.9 in48 mm of precipitation and 17 in44 cm of snow in a typical February.
- Record high
- 59°15° (2026)
- Record low
- −46°−43° (1950)
- Heating degree days
- 1175
- Cooling degree days
- 0
Ketchum in March
Highs average 43°6° and lows 19°−7°, with 1.8 in45 mm of precipitation and 11 in27 cm of snow in a typical March.
- Record high
- 72°22° (2026)
- Record low
- −28°−33° (1960)
- Heating degree days
- 1065
- Cooling degree days
- 0
Ketchum in April
Highs average 52°11° and lows 27°−3°, with 1.2 in30 mm of precipitation and 3 in8 cm of snow in a typical April.
- Record high
- 79°26° (1946)
- Record low
- −4°−20° (1938)
- Heating degree days
- 768
- Cooling degree days
- 0
Ketchum in May
Highs average 62°16° and lows 35°2°, with 1.8 in45 mm of precipitation and 0.2 in0.5 cm of snow in a typical May.
- Record high
- 89°32° (2003)
- Record low
- 5°−15° (1944)
- Heating degree days
- 523
- Cooling degree days
- 0
Ketchum in June
Highs average 70°21° and lows 40°4°, with 1.3 in32 mm of precipitation in a typical June.
- Record high
- 97°36° (1974)
- Record low
- 16°−9° (2026)
- Heating degree days
- 311
- Cooling degree days
- 5
Ketchum in July
Highs average 80°27° and lows 45°7°, with 0.55 in14 mm of precipitation in a typical July.
- Record high
- 98°37° (2002)
- Record low
- 14°−10° (2010)
- Heating degree days
- 114
- Cooling degree days
- 38
Ketchum in August
Highs average 79°26° and lows 44°6°, with 0.5 in13 mm of precipitation in a typical August.
- Record high
- 96°36° (1961)
- Record low
- 15°−9° (2026)
- Heating degree days
- 140
- Cooling degree days
- 19
Ketchum in September
Highs average 69°21° and lows 36°2°, with 1 in26 mm of precipitation in a typical September.
- Record high
- 93°34° (1955)
- Record low
- 11°−12° (1954)
- Heating degree days
- 374
- Cooling degree days
- 1
Ketchum in OctoberThis month
Highs average 56°13° and lows 28°−2°, with 1.4 in36 mm of precipitation and 1.6 in4.1 cm of snow in a typical October.
- Record high
- 85°29° (1971)
- Record low
- −3°−19° (1943)
- Heating degree days
- 719
- Cooling degree days
- 0
Ketchum in November
Highs average 41°5° and lows 17°−8°, with 1.2 in31 mm of precipitation and 10 in26 cm of snow in a typical November.
- Record high
- 69°21° (1949)
- Record low
- −25°−32° (1955)
- Heating degree days
- 1071
- Cooling degree days
- 0
Ketchum in December
Highs average 30°−1° and lows 9°−13°, with 2.6 in65 mm of precipitation and 32 in81 cm of snow in a typical December.
- Record high
- 60°16° (1939)
- Record low
- −37°−38° (1964)
- Heating degree days
- 1403
- Cooling degree days
- 0