AI-generatedSun Valley (Ketchum), Idaho at a glance
- Best time
- Jun, Aug – Sep
- Warmest month
- Jul · 28°
- Sunshine a year
- 2,690 h
- Rain a year
- 432 mm
- Climate
- Continental
- Time zone
- UTC−7 / UTC−6
- Elevation
- 1,784 m
Climate in Sun Valley (Ketchum), Idaho
Sun Valley (Ketchum), Idaho has warm to hot summers and cold winters with occasional snow. July is the warmest month with average highs of 28 °C, while January is the coolest at −3 °C. With around 2,690 hours of sunshine a year, Sun Valley (Ketchum), Idaho is sunny; July is the sunniest month with 11.2 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Good
Best time to visit: June, August – September
Best for skiing: December – April
Keep in mindSnow
A typical day in October
- Morning, 08:00: about 1°
- Midday, 13:00: about 11°
- Afternoon, 16:00: about 12°
- Evening, 20:00: about 7°
- Night, 23:00: about 4°
07:5018:56
Cold evenings: bring a warm jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
Light for photos in October
- Golden hour
- Morning 07:32–08:29 · evening 18:17–19:14
- Blue hour
- Morning 07:21–07:32 · evening 19:14–19:25
Golden hour: the sun between 4° below and 6° above the horizon; blue hour: 6° to 4° below it. Times for the 15th of the month; mountains and clouds shift the light.
What is the weather like in Sun Valley (Ketchum), Idaho in October?
In October, Sun Valley (Ketchum), Idaho is cool: daytime highs average 12 °C, and nights cool down to about 0 °C. The sun shines for around 7 hours a day. Rain falls on about 6 days, adding up to 34 mm. Snow falls on about 2 days. All in all, October is a good month for a holiday in Sun Valley (Ketchum), Idaho.
More details for October
- Daylight
- 11 h 6 min07:50 – 18:56
- UV index
- 4 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 13 km/haverage daily peakAll months
- Cloud cover
- 42 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 2 days1 cm or more of fresh snowAll months
- Time zone
- UTC−6America/Boise
How the score comes together
- Temperatureweight 50 %64 %
- Sunshineweight 20 %60 %
- Few rainy daysweight 30 %88 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Mountain air”.
What to pack in October
- Sunscreen
- A jumper for the evenings
- Hat, scarf & gloves
Sunshine hours in Sun Valley (Ketchum), Idaho
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 6.6 of 11.1 hours of daylight in Sun Valley (Ketchum), Idaho, 59 % of the day.
Sunshine hours: estimated from radiation data (ERA5, 1996–2025) and calibrated against measured station values; no weather station is close enough here. Daylight is the time from sunrise to sunset on the 15th of the month.
UV index in Sun Valley (Ketchum), Idaho
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 4 · moderateAround midday seek shade; use sunscreen, a hat and sunglasses.
The sun is strongest in June (UV 10).
Minutes until sunburn in October
- Very fair skin
- about 35 min
- Fair skin
- about 45 min
- Light brown skin
- about 65 min
- Olive skin
- about 80 min
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in Sun Valley (Ketchum), Idaho: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, Sun Valley (Ketchum), Idaho has about 6 rainy days with 34 mm of rain in total.
Wind and clouds in Sun Valley (Ketchum), Idaho
How breezy and how cloudy Sun Valley (Ketchum), Idaho is through the year. Tap a month to select it on the whole page.
Wind
Typical daily peak of the wind in km/h: what the afternoon breeze usually reaches, not the gusts.
In October, the wind in Sun Valley (Ketchum), Idaho typically peaks at 13 km/h during the day: Beaufort 3, light breeze.
Clouds
Average share of the sky covered by cloud, day and night.
In October, cloud covers on average 42 % of the sky over Sun Valley (Ketchum), Idaho: mostly sunny, with about 6.6 hours of sunshine a day.
Wind: mean daily maximum of the hourly wind 10 m above ground (ERA5, 1996–2025). Gusts are stronger, and the model grid of about 28 km smooths out local effects such as capes and valley winds. Clouds: mean total cloud cover of all layers over day and night (ERA5, 1996–2025). Thin high cloud counts as cover even when the sun still shines through.
Heat and humidity in Sun Valley (Ketchum), Idaho
How often the day gets hot in Sun Valley (Ketchum), Idaho (30 °C and more), and in which months heat and humidity come together. Tap a month to select it.
Heat calendar
- pleasant
- some hot or muggy days
- often muggy
- often hot
- hot and muggy
In October, Sun Valley (Ketchum), Idaho has about 0 hot days, with an average daytime high of 12 °C: pleasant. Heat plays no part this month.
Hot days reach at least 30 °C; a month counts as muggy when the mean dew point reaches 18 °C on at least 15 days. Averages from ERA5 and ERA5-Land, 1996–2025. Muggy nights through the year
Snow in Sun Valley (Ketchum), Idaho
When Sun Valley (Ketchum), Idaho is likely to be white: the chance of seeing snow during a week's stay, the days with fresh snow and how much falls. Tap a month to select it.
Snow calendar
- hardly any
- possible
- likely
- very likely
In October, Sun Valley (Ketchum), Idaho has about 2 days with at least 1 cm of fresh snow, 6 cm in total. The chance of seeing snow during a week's stay is 25 out of 100: possible. On the slopes at about 2,400 m, the ski season usually runs Dec – Apr.
Snow days bring at least 1 cm of fresh snow. Fresh snow comes from ERA5 snowfall (1996–2025) at the height of the place, not on the slopes above it; the snow chance also weighs whether the snow settles. An estimate from climate averages, not a snow report.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Nights and sleep in Sun Valley (Ketchum), Idaho
How warm the nights get in each month, from the mean night-time low. Tap a month for details.
- Frost below 0°
- Cold 0–8°
- Cool 8–15°
ColdOctober: nights around 0°. The room should be heated.
The coolest nights are in December (−14°), the warmest in July (12°). Nights fall below 8 °C on average from September to June, so the room should be heated.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|
| JanuaryJan | 25 | −3° | −14° | 4.5 h | 9 | 53 |
| FebruaryFeb | 30 | −1° | −12° | 5.5 h | 8 | 44 |
| MarchMar | 31 | 3° | −8° | 6.6 h | 9 | 47 |
| AprilApr | 45 | 8° | −4° | 7.7 h | 9 | 36 |
| MayMay | 81 | 15° | 1° | 8.6 h | 9 | 44 |
| JuneJun | 96 | 21° | 7° | 10.4 h | 6 | 25 |
| JulyJul | 81 | 28° | 12° | 11.2 h | 3 | 7 |
| AugustAug | 90 | 26° | 11° | 9.9 h | 3 | 12 |
| SeptemberSep | 97 | 21° | 7° | 8.4 h | 4 | 21 |
| OctoberOct | 70 | 12° | 0° | 6.6 h | 6 | 34 |
| NovemberNov | 30 | 4° | −8° | 4.9 h | 7 | 39 |
| DecemberDec | 21 | −2° | −14° | 4.1 h | 10 | 70 |
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences
43.68° N, 114.36° W · 1,784 m · America/Boise
Best time to visit Sun Valley (Ketchum), Idaho
The best time to visit Sun Valley (Ketchum), Idaho is in June and from August to September. Hiking and mountain trips are best from May to June and from August to September, when the trails are largely free of snow. The wettest month is December with 70 mm of precipitation.
Sun Valley (Ketchum), Idaho through the seasons
How the weather changes over the seasons, with averages for each.
Sun Valley (Ketchum), Idaho in spring
Mar – May
Fair
- 3–15 °C by day
- 8 h of sun a day
- 27 rainy days in all
Sun Valley (Ketchum), Idaho in summer
Jun – Aug
Excellent
- 21–28 °C by day
- 11 h of sun a day
- 11 rainy days in all
Sun Valley (Ketchum), Idaho in autumn
Sep – Nov
Good
- 4–21 °C by day
- 7 h of sun a day
- 17 rainy days in all
Sun Valley (Ketchum), Idaho in winter
Dec – Feb
Poor
- -3–-1 °C by day
- 5 h of sun a day
- 26 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in Sun Valley (Ketchum), Idaho for you.
Your best months: June, September
Based on the climate averages; tap a month to see its details.
Compare two months in Sun Valley (Ketchum), Idaho
Pick two months to see how the weather differs. A tick marks the clearly better value; for temperatures it depends on your plans.
September has the better holiday weather in Sun Valley (Ketchum), Idaho: score 97 against 70. In September, days are 9 °C warmer than in October. September has 2 fewer rainy days. The sun shines 2 hours longer a day in September.
| Month | October | September |
|---|---|---|
| Weather score | 70 | 97better |
| Day high | 12° | 21° |
| Night low | 0° | 7° |
| Sunshine | 6.6 h | 8.4 hbetter |
| Rainy days | 6 | 4better |
| Rainfall | 34 mm | 21 mmbetter |
Based on the climate averages 1996–2025.
Which month for what?
Hiking & mountain trips
May – Jun, Aug – Sep
13–27 °C in the village, little snow
Snow
Oct – Apr
Snow on 2 or more days
Best for skiing
Dec – Apr
Estimated snow conditions on slopes at about 2,400 m, from snowfall, temperature and sunshine. A climate estimate, not a snow report.
Sun Valley (Ketchum), Idaho month by month
The typical weather for every month at a glance.
25January-3° · 5 h
In January, Sun Valley (Ketchum), Idaho is freezing cold: daytime highs average −3 °C, and nights often drop below freezing (−14 °C). Expect around 5 hours of sunshine a day. Precipitation, often as snow, falls on about 9 days, totalling 53 mm. Snow falls on about 8 days. All in all, January is not an ideal month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in January30February-1° · 6 h
In February, Sun Valley (Ketchum), Idaho is freezing cold: daytime highs average −1 °C, and nights often drop below freezing (−12 °C). Expect around 6 hours of sunshine a day. Precipitation, often as snow, falls on about 8 days, totalling 44 mm. Snow falls on about 7 days. All in all, February is not an ideal month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in February31March3° · 7 h
In March, Sun Valley (Ketchum), Idaho is cold: daytime highs average 3 °C, and nights often drop below freezing (−8 °C). The sun shines for around 7 hours a day. Precipitation, often as snow, falls on about 9 days, totalling 47 mm. Snow falls on about 7 days. All in all, March is not an ideal month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in March45April8° · 8 h
In April, Sun Valley (Ketchum), Idaho is cold: daytime highs average 8 °C, and nights often drop below freezing (−4 °C). The sun shines for around 8 hours a day. Rain falls on about 9 days, adding up to 36 mm. Snow falls on about 3 days. All in all, April is a so-so month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in April81May15° · 9 h
In May, Sun Valley (Ketchum), Idaho is cool: daytime highs average 15 °C, and nights cool down to about 1 °C. The sun shines for around 9 hours a day. Rain is frequent, with about 9 rainy days and 44 mm in total. Snow falls on about 2 days. All in all, May is an excellent month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in May96June21° · 10 h
In June, Sun Valley (Ketchum), Idaho is warm: daytime highs average 21 °C, and nights cool down to about 7 °C. With around 10 hours of sunshine a day, there is plenty of sun. Rain falls on about 6 days, adding up to 25 mm. All in all, June is an excellent month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in June81July28° · 11 h
In July, Sun Valley (Ketchum), Idaho is hot: daytime highs average 28 °C, and nights cool down to about 12 °C. With around 11 hours of sunshine a day, there is plenty of sun. Rain is rare: about 3 days bring 7 mm in total. On about 8 days the thermometer climbs to 30 °C or more. All in all, July is an excellent month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in July90August26° · 10 h
In August, Sun Valley (Ketchum), Idaho is warm: daytime highs average 26 °C, and nights cool down to about 11 °C. With around 10 hours of sunshine a day, there is plenty of sun. Rain is rare: about 3 days bring 12 mm in total. All in all, August is an excellent month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in August97September21° · 8 h
In September, Sun Valley (Ketchum), Idaho is mild: daytime highs average 21 °C, and nights cool down to about 7 °C. The sun shines for around 8 hours a day. Rain is rare: about 4 days bring 21 mm in total. All in all, September is an excellent month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in September70October12° · 7 h
In October, Sun Valley (Ketchum), Idaho is cool: daytime highs average 12 °C, and nights cool down to about 0 °C. The sun shines for around 7 hours a day. Rain falls on about 6 days, adding up to 34 mm. Snow falls on about 2 days. All in all, October is a good month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in October30November4° · 5 h
In November, Sun Valley (Ketchum), Idaho is cold: daytime highs average 4 °C, and nights often drop below freezing (−8 °C). Expect around 5 hours of sunshine a day. Precipitation, often as snow, falls on about 7 days, totalling 39 mm. Snow falls on about 5 days. All in all, November is not an ideal month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in November21December-2° · 4 h
In December, Sun Valley (Ketchum), Idaho is freezing cold: daytime highs average −2 °C, and nights often drop below freezing (−14 °C). Expect around 4 hours of sunshine a day. Precipitation, often as snow, falls on about 10 days, totalling 70 mm. Snow falls on about 9 days. All in all, December is not an ideal month for a holiday in Sun Valley (Ketchum), Idaho.
Sun Valley (Ketchum), Idaho in DecemberSun Valley (Ketchum), Idaho compared
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Sun Valley (Ketchum) vs. Boise
In October Boise has the better holiday weather (score 93 vs. 70). During the day Boise is 6 °C warmer than Sun Valley (Ketchum).
| in October | Sun Valley (Ketchum) | Boise |
|---|---|---|
| Holiday score | 70 | 93 |
| Daytime high | 12° | 18° |
| Sunshine | 7 h | 7 h |
| Rainy days | 6 | 4 |
| Best time | Jun, Aug – Sep | May – Jun, Sep – Oct |
Through the year
USA in October: the best places
In October, Sun Valley (Ketchum), Idaho ranks 16 among the 31 nearest destinations in this country.
- Las Vegas26°99
- 2Mariposa (Yosemite)23°98
- 3Page (Lake Powell)21°96
- 4Sacramento25°96
- 5San Jose23°96
- 6Reno19°95
- 7Moab21°95
- 8Napa Valley24°95
- 16Sun Valley (Ketchum)This page12°70
Planning a trip to Sun Valley (Ketchum), Idaho
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Sun Valley (Ketchum), Idaho in the school holidays
How the weather suits the usual holiday periods. Dates vary by school and region, so each holiday uses the months it usually falls in.
Sun Valley (Ketchum), Idaho has its best school-holiday weather during the Easter holidays (ski score 93) and its weakest during October half-term (score 70).
- 93
Easter holidays
Mar – Apr
Excellent · ski conditionsBest holidays
- 6 °C by day
- 7.4 h of sun a day
- 9 rainy days a month
Good for: Skiing
- 84
May half-term
May – Jun
Excellent
- 16 °C by day
- 9.0 h of sun a day
- 9 rainy days a month
Good for: Sightseeing & walks
- 87
Summer holidays
Jul – Aug
Excellent
- 27 °C by day
- 10.4 h of sun a day
- 3 rainy days a month
- 70
October half-term
Oct
Good
- 12 °C by day
- 6.6 h of sun a day
- 6 rainy days a month
Keep in mind: Snow
- 87
Christmas holidays
Dec – Jan
Excellent · ski conditions
- −2 °C by day
- 4.3 h of sun a day
- 9 rainy days a month
Good for: Skiing
Based on the climate averages 1996–2025.
Getting there
Flying from
- Nonstop flight
- about 9 h 45 min
- Distance
- 7,680 km
- Time zone
- UTC−6
- Jet lag
- About 5 days (7 h west)
Rule of thumb for flying west: for a few days before, stay up a little later, and get afternoon and evening light at your destination.
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about Sun Valley (Ketchum), Idaho
When is the best time to visit Sun Valley (Ketchum), Idaho?
The best time to visit Sun Valley (Ketchum), Idaho is in June and from August to September. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
What is the warmest month in Sun Valley (Ketchum), Idaho?
July is the warmest month, with average highs of 28 °C and nights around 12 °C. January is the coolest month at −3 °C.
When does it rain most in Sun Valley (Ketchum), Idaho?
The wettest month is December with 70 mm of precipitation. The driest month is July with 7 mm.
How many hours of sunshine does Sun Valley (Ketchum), Idaho get?
Sun Valley (Ketchum), Idaho gets around 2,690 hours of sunshine a year. The sunniest month is July with 11.2 hours a day; in December there are 4.1 hours a day.
What time zone is Sun Valley (Ketchum), Idaho in?
Sun Valley (Ketchum), Idaho uses the time zone America/Boise: UTC−7 in January and UTC−6 in July.
How long is the flight from London to Sun Valley (Ketchum), Idaho?
A nonstop flight from London to Sun Valley (Ketchum), Idaho takes about 9 h 45 min, for a straight-line distance of about 7,680 km.
Which school holidays are best for Sun Valley (Ketchum), Idaho?
Sun Valley (Ketchum), Idaho has its best school-holiday weather during the Easter holidays (ski score 93) and its weakest during October half-term (score 70). Holiday ratings (0–100): Easter holidays 93 (Ski), May half-term 84, Summer holidays 87, October half-term 70, Christmas holidays 87 (Ski).
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