Ketchum, Idaho climate: Normal weather by month, frost dates and records
Ketchum's normal year runs from 8°F January nights to 80°F July afternoons, with 17.3 inches of precipitation and 102 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.6°C, January lows of −13°C, July highs of 27°C, 440 mm of precipitation a year.
- NOAA stationKetchum Ranger Station
- Station IDUSC00104845
- Location43.68°N 114.36°W
- Elevation5,890 ft (1,795 m)
- Population3,609
On October 14, the normal high in Ketchum is 57°F and the normal low 28°F, and the chance of measurable rain or snow is 16%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ketchum.
- Jan 31° 8°
- Feb 35° 11°
- Mar 43° 19°
- Apr 52° 27°
- May 62° 35°
- Jun 70° 40°
- Jul 80° 45°
- Aug 79° 44°
- Sep 69° 36°
- Oct 56° 28°
- Nov 41° 17°
- Dec 30° 9°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Ketchum each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of 8°F. The most precipitation falls in December (2.57 in), the least in August (0.50 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 8°F | 19.6°F | 2.25 | 27.0 | 10 | <1 | 31 | 9 h 20 min |
| February | 35°F | 11°F | 23.1°F | 1.88 | 17.2 | 9 | <1 | 28 | 10 h 30 min |
| March | 43°F | 19°F | 30.6°F | 1.76 | 10.5 | 8 | <1 | 30 | 11 h 50 min |
| April | 52°F | 27°F | 39.4°F | 1.17 | 3.2 | 7 | <1 | 25 | 13 h 20 min |
| May | 62°F | 35°F | 48.2°F | 1.78 | 0.2 | 8 | <1 | 13 | 14 h 40 min |
| June | 70°F | 40°F | 54.8°F | 1.26 | 0.0 | 7 | <1 | 5 | 15 h 30 min |
| July | 80°F | 45°F | 62.6°F | 0.55 | 0.0 | 4 | 2 | 1 | 15 h 10 min |
| August | 79°F | 44°F | 61.1°F | 0.50 | 0.0 | 4 | 1 | 2 | 14 h |
| September | 69°F | 36°F | 52.6°F | 1.01 | 0.0 | 4 | <1 | 9 | 12 h 30 min |
| October | 56°F | 28°F | 41.8°F | 1.40 | 1.6 | 5 | <1 | 25 | 11 h 10 min |
| November | 41°F | 17°F | 29.3°F | 1.21 | 10.3 | 6 | <1 | 30 | 9 h 40 min |
| December | 30°F | 9°F | 19.7°F | 2.57 | 32.0 | 11 | <1 | 31 | 9 h |
| Year (annual) | 54°F | 27°F | 40.2°F | 17.34 | 102.0 | 84 | 4 | 229 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −13°C | −6.9°C | 57 mm | 69 cm |
| February | 2°C | −12°C | −4.9°C | 48 mm | 44 cm |
| March | 6°C | −7°C | −0.8°C | 45 mm | 27 cm |
| April | 11°C | −3°C | 4.1°C | 30 mm | 8 cm |
| May | 16°C | 2°C | 9.0°C | 45 mm | 1 cm |
| June | 21°C | 4°C | 12.7°C | 32 mm | 0 cm |
| July | 27°C | 7°C | 17.0°C | 14 mm | 0 cm |
| August | 26°C | 6°C | 16.2°C | 13 mm | 0 cm |
| September | 21°C | 2°C | 11.4°C | 26 mm | 0 cm |
| October | 13°C | −2°C | 5.4°C | 36 mm | 4 cm |
| November | 5°C | −8°C | −1.5°C | 31 mm | 26 cm |
| December | −1°C | −13°C | −6.8°C | 65 mm | 81 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00104845; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Ketchum?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, July has the fewest days with rain (4).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00104845.
How hot and how cold does it get in Ketchum?
In a normal year in Ketchum, 4 days a year reach 90°F, 229 nights fall to 32°F or colder and 84 days bring measurable precipitation.
- Days at 90°F or more
- 4a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 229a normal year
- Days that stay below freezing
- 49high of 32°F or less
- Days with 0.01 inch of precipitation
- 84a normal year
- Days with 1 inch of snow or more
- 30a normal year
The highest temperature in this station's record (since 1937) is 98°F, on July 13, 2002; the lowest is −46°F, on February 2, 1950.
The wettest calendar year on that record is 1983, with 27.95 in; the snowiest season is 1951–52, with 244.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00104845; records: ACIS (NOAA Regional Climate Centers), station USC00104845. Records use complete months only; a month missing more than three days is left out.
How sunny is Ketchum?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Ketchum, 4.6 kWh per square metre a day. July is the sunniest month (90%) and December the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.0 |
| February | 72% | 2.9 |
| March | 72% | 4.1 |
| April | 74% | 5.4 |
| May | 76% | 6.4 |
| June | 84% | 7.5 |
| July | 90% | 7.7 |
| August | 89% | 6.6 |
| September | 86% | 5.1 |
| October | 80% | 3.5 |
| November | 72% | 2.1 |
| December | 66% | 1.5 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Ketchum need?
A normal year in Ketchum brings 9,068 heating degree days, 69% more than the median U.S. place (5,373), and 63 cooling degree days, 93% fewer than the median (908). Ten months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,127 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,406 | 0 |
| February | 1,175 | 0 |
| March | 1,065 | 0 |
| April | 768 | 0 |
| May | 523 | 1 |
| June | 311 | 5 |
| July | 114 | 38 |
| August | 140 | 19 |
| September | 374 | 1 |
| October | 719 | 0 |
| November | 1,071 | 0 |
| December | 1,403 | 0 |
| Year (annual) | 9,068 | 63 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00104845. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Ketchum been warmer than normal lately?
2024 averaged 40.7°F, 0.5°F above the 1991-2020 normal of 40.2°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2024 | 40.7°F | +0.5°F | – | – |
Over 78 complete years from 1909 to 2024, the station's annual mean temperature rose at a fitted 3.1°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00104845; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Ketchum's climate compare?
Ketchum is warmer than 5 of the other 84 places with their own NOAA record in Idaho, and wetter than 46. Across the 7,247 U.S. stations with normals, its annual mean of 40.2°F is warmer than 6%.
In the Köppen classification computed from these normals, Ketchum is Dsb: continental, dry-summer, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Ketchum share this climate record?
Sun Valley has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Sun Valley, ID1,771 people · 1 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Ketchum's climate
What is the coldest month in Ketchum?
January, with a normal high of 31°F and a normal low of 8°F. The warmest is July (80°F by day, 45°F at night).
Does it snow in Ketchum?
Yes: 102 inches in a normal year, falling on 38 days with 0.1 inch or more, the most in December (32.0 inches).
What is the rainiest month in Ketchum?
December, with 2.57 in of precipitation in a normal year; the driest is August with 0.50 in.
What plant hardiness zone is Ketchum in?
The USDA's 2023 map puts Ketchum in zone 5b in ZIP code 83353, the nearest ZIP area. By the same method at Ketchum's NOAA station, the coldest night of a typical year reaches −12°F (19 years, 1991-2020): zone 5b.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Bellevue, ID16 miles from this station, 46.9°F a year
- Picabo, ID30 miles from this station, 42.4°F a year
- Fairfield, ID32 miles from this station, 42.1°F a year
- Chilly Barton Flat, ID34 miles from this station, 41.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made