Photo: Stephen Marks - (WT-en) StephenM at English Wikivoyage · Public domainKetchum gets about 102 inches of snow a winter, more than 97% of U.S. towns
A typical July afternoon reaches 83°, a January night drops to 8°, and about 102 inches of snow falls in a normal winter.
A year in Ketchum at a glance
Each month’s typical high and low, and what it brings.
What stands out about Ketchum’s climate
Compared with towns across the U.S., with Ketchum’s place in Idaho beside it.
What a year in Ketchum feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze is possible in every month
About 229 nights a year fall to 32° or below, and 21 to 0° or below. Frost and day counts come from NOAA’s station at Ketchum Rs, ID, 0.7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Ketchum’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −12°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 102 inches of snow a winter
Snow, measured at Ketchum Rs, ID, falls mostly in December. Precipitation (rain plus melted snow) adds up to 17 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 84 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Ketchum
99% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from September through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Ketchum Rs, ID.
Living with Ketchum’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 5b, and frost can come in any month. The longest frost-free stretch in half of years is about 77 days.
Months with highs of 62–84° and lows of 40° or more: July and August. 4.3 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Ketchum from natural hazards, avalanches are the largest share (64%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Ketchum and similar climates
TownRatings has no climate map of the towns around Ketchum yet.
Climates most like Ketchum’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Ketchum, ID | 8° | 83° | 17" | 102" |
| Lewistown, MT | 12° | 82° | 18" | 112" |
| Monument, CO | 14° | 83° | 22" | 121" |
| Jackson, WY | 6° | 80° | 19" | 78" |
| Flagstaff, AZ | 16° | 84° | 18" | 90" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Ketchum averaged 1.4° warmer than the 1900s. The biggest change is in January (+2.8°).
A bigger shift than in 50% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Ketchum compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Ketchum’s place among Idaho’s.
Ketchum weather by month
Highs, lows and precipitation from NOAA’s grid at Ketchum’s center; snow, wet days and snow on the ground from Ketchum Rs, ID. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 32° | 8° | 2.0" | 27.0" | 10 | 14° – 26° |
| February | 36° | 11° | 1.8" | 17.2" | 9 | 18° – 32° |
| March | 44° | 19° | 1.6" | 10.5" | 8 | 26° – 38° |
| April | 53° | 27° | 1.1" | 3.2" | 7 | 33° – 45° |
| May | 63° | 34° | 1.9" | 0.2" | 8 | 42° – 55° |
| June | 72° | 39° | 1.3" | 0.0" | 7 | 50° – 62° |
| July | 83° | 46° | 0.5" | 0.0" | 4 | 54° – 69° |
| August | 81° | 44° | 0.5" | 0.0" | 4 | 57° – 66° |
| September | 71° | 37° | 0.9" | 0.0" | 4 | 51° – 58° |
| October | 57° | 28° | 1.2" | 1.6" | 5 | 34° – 49° |
| November | 41° | 19° | 1.5" | 10.3" | 6 | 20° – 37° |
| December | 31° | 9° | 2.6" | 32.0" | 11 | 14° – 24° |
| Year | 55° | 27° | 16.9" | 102.0" | 84 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 20° to 37°. September is the most reliable, staying within 7°.
Where Ketchum’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Ketchum’s center.
- Snow: Ketchum Rs, ID (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ketchum Rs, ID, 0.7 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Ketchum’s climate
What is the weather like in Ketchum?
A typical July afternoon reaches 83°, a January night drops to 8°, and about 102 inches of snow falls in a normal winter. Colder January nights than 95% of U.S. towns; cooler July afternoons than 76% of U.S. towns.
How cold does it get in Ketchum in winter?
January nights average 8°. About 229 nights a year reach 32° or below and 21 reach 0° or below. In the coldest January of the last 30 years the month averaged 14°.
How much snow does Ketchum get?
About 102 inches in a normal winter at Ketchum Rs, ID, most of it in December.
How hot does it get in Ketchum?
July, with a typical high of 83° and a low of 46°. About 4 days a year reach 90° (Ketchum Rs, ID).
When is the first and last frost in Ketchum?
There is no reliable frost-free season: at Ketchum Rs, ID, every month has nights at 32° or below, about 229 a year. In half of years the longest stretch without a freeze is about 77 days.
What growing zone is Ketchum in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −12°.
What is the best time of year to visit Ketchum?
By one simple rule (highs of 62–84° and lows of 40° or more), July and August. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Ketchum getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 50% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Ketchum.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.