Photo: Bobjgalindo · CC BY-SA 4.0Nights turn raw in Swan Valley each January, colder than in 93% of U.S. towns
The warmest part of a July day comes in at 83° on average. From frosty January to warm July, readings climb 72°. Its yearly precipitation falls short of 91% of U.S. towns. The heating season runs October to April: each of those months averages under 50°.
A year in Swan Valley at a glance
Each month’s typical high and low, and what it brings.
What stands out about Swan Valley’s climate
Compared with towns across the U.S., with Swan Valley’s place in Idaho beside it.
What a year in Swan Valley 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 198 nights a year fall to 32° or below, and 16 to 0° or below. Frost and day counts come from NOAA’s station at Swan Valley, ID, 2.3 miles from the town’s center, at about the same height.
The 2023 USDA map puts Swan Valley’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −16°. 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 66 inches of snow a winter
Snow, measured at Idaho Falls 16 Se, ID, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 18 inches a year; May is the wettest month and July the driest. Rain or snow falls on about 97 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Swan Valley
98% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October 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 Swan Valley, ID.
Living with Swan Valley’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 5a, and frost can come in any month. The longest frost-free stretch in half of years is about 69 days.
Months with highs of 62–84° and lows of 40° or more: June, July and August. 7.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Swan Valley from natural hazards, avalanches are the largest share (40%); heat waves, cold waves, winter storms and ice storms together are 8%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Swan Valley and similar climates
TownRatings has no climate map of the towns around Swan Valley yet.
Climates most like Swan Valley’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 |
|---|---|---|---|---|
| Swan Valley, ID | 11° | 83° | 18" | 66" |
| Gleneagle, CO | 14° | 84° | 21" | 55" |
| Great Falls, MT | 13° | 84° | 13" | 66" |
| Laramie, WY | 12° | 81° | 12" | 64" |
| 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 Swan Valley averaged 1.1° warmer than the 1900s. The biggest change is in March (+3.1°).
A smaller shift than in 71% 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 Swan Valley compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Swan Valley’s place among Idaho’s.
Swan Valley weather by month
Highs, lows and precipitation from NOAA’s grid at Swan Valley’s center; snow, wet days and snow on the ground from Idaho Falls 16 Se, ID. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 29° | 11° | 1.7" | 17.0" | 10 | 30 | 12° – 26° |
| February | 34° | 13° | 1.2" | 11.8" | 9 | 25 | 18° – 30° |
| March | 44° | 22° | 1.4" | 7.6" | 9 | 18 | 26° – 39° |
| April | 54° | 28° | 1.7" | 2.9" | 10 | 2 | 35° – 46° |
| May | 64° | 36° | 2.2" | 0.9" | 10 | 0 | 45° – 55° |
| June | 73° | 42° | 1.8" | 0.2" | 8 | 0 | 52° – 62° |
| July | 83° | 48° | 0.9" | 0.0" | 5 | 0 | 56° – 72° |
| August | 82° | 46° | 1.1" | 0.0" | 6 | 0 | 58° – 69° |
| September | 73° | 38° | 1.4" | 0.0" | 5 | 0 | 52° – 60° |
| October | 58° | 29° | 1.6" | 1.7" | 7 | 1 | 35° – 50° |
| November | 42° | 20° | 1.5" | 7.6" | 8 | 10 | 22° – 39° |
| December | 30° | 12° | 1.6" | 16.0" | 11 | 25 | 17° – 27° |
| Year | 55° | 29° | 18.0" | 65.7" | 97 | 111 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 22° to 39°. September is the most reliable, staying within 8°.
Where Swan Valley’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 Swan Valley’s center.
- Snow: Idaho Falls 16 Se, ID.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Swan Valley, ID, 2.3 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 Swan Valley’s climate
What is the weather like in Swan Valley?
A typical July afternoon reaches 83°, a January night drops to 11°, and about 66 inches of snow falls in a normal winter. Colder January nights than 93% of U.S. towns; cooler July afternoons than 72% of U.S. towns.
How cold does it get in Swan Valley in winter?
January nights average 11°. About 198 nights a year reach 32° or below and 16 reach 0° or below. In the coldest January of the last 30 years the month averaged 12°.
How much snow does Swan Valley get?
About 66 inches in a normal winter at Idaho Falls 16 Se, ID, most of it in January and December, with snow on the ground about 111 days a year.
How hot does it get in Swan Valley?
July, with a typical high of 83° and a low of 48°. About 14 days a year reach 90° (Swan Valley, ID).
When is the first and last frost in Swan Valley?
There is no reliable frost-free season: at Swan Valley, ID, every month has nights at 32° or below, about 198 a year. In half of years the longest stretch without a freeze is about 69 days.
What growing zone is Swan Valley in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −16°.
What is the best time of year to visit Swan Valley?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July and August. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Swan Valley getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 71% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Swan Valley.
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.