Big Falls Inn · Photo: Kathleen Pilley · CC BY-SA 3.0Warm River has colder winter nights than 93% of U.S. towns
The warmest part of a July day comes in at 82° on average. It is a dry place: less rain and snow fall here than on 90% of U.S. towns. Warming shows here too: 1.4° more than in 1901–2000, led by March. The frost-free window for a garden runs roughly May 21 to September 21.
A year in Warm River at a glance
Each month’s typical high and low, and what it brings.
What stands out about Warm River’s climate
Compared with towns across the U.S., with Warm River’s place in Idaho beside it.
What a year in Warm River feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 121 frost-free days a year
In half of years the last 32° night comes by May 21 and the first by September 21. Frost and day counts come from NOAA’s station at Ashton 1n, ID, 8 miles from the town’s center, 260 ft lower.
The 2023 USDA map puts Warm River’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −17°. 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 70 inches of snow a winter
Snow, measured at Ashton 1n, ID, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 20 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 78 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Warm River
97% 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 Ashton 1n, ID.
Living with Warm River’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
121 frost-free days in zone 5a. The last frost comes by May 21 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 21.
Months with highs of 62–84° and lows of 40° or more: June, July and August.
Parks & trails →Of the yearly building losses FEMA expects in Warm River from natural hazards, river flooding is the largest share (43%); heat waves, cold waves, winter storms and ice storms together are 3%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Warm River and similar climates
TownRatings has no climate map of the towns around Warm River yet.
Climates most like Warm River’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 |
|---|---|---|---|---|
| Warm River, ID | 11° | 82° | 20" | 70" |
| Gleneagle, CO | 14° | 84° | 21" | 55" |
| Whitefish, MT | 17° | 82° | 18" | 63" |
| Flagstaff, AZ | 16° | 84° | 18" | 90" |
| Laramie, WY | 12° | 81° | 12" | 64" |
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 Warm River averaged 1.4° warmer than the 1900s. The biggest change is in March (+3.7°).
A bigger shift than in 52% 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 Warm River compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Warm River’s place among Idaho’s.
Warm River weather by month
Highs, lows and precipitation from NOAA’s grid at Warm River’s center; snow, wet days and snow on the ground from Ashton 1n, ID. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 28° | 11° | 2.2" | 19.8" | 9 | 31 | 13° – 27° |
| February | 33° | 13° | 1.6" | 10.7" | 7 | 29 | 17° – 30° |
| March | 43° | 21° | 1.5" | 5.3" | 7 | 25 | 23° – 38° |
| April | 53° | 28° | 1.8" | 2.0" | 7 | 4 | 32° – 46° |
| May | 64° | 36° | 2.2" | 0.0" | 8 | 0 | 45° – 55° |
| June | 72° | 43° | 1.8" | 0.0" | 6 | 0 | 51° – 64° |
| July | 82° | 48° | 0.9" | 0.0" | 3 | 0 | 55° – 72° |
| August | 82° | 46° | 0.9" | 0.0" | 4 | 0 | 58° – 67° |
| September | 71° | 38° | 1.3" | 0.0" | 5 | 0 | 51° – 59° |
| October | 56° | 29° | 1.6" | 1.6" | 5 | 1 | 33° – 49° |
| November | 40° | 19° | 1.7" | 10.5" | 7 | 10 | 20° – 38° |
| December | 28° | 12° | 2.3" | 20.2" | 10 | 26 | 15° – 26° |
| Year | 54° | 29° | 19.7" | 70.1" | 78 | 125 |
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 38°. September is the most reliable, staying within 8°.
Where Warm River’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 Warm River’s center.
- Snow: Ashton 1n, ID.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ashton 1n, ID, 8 miles from the town’s center, 260 ft lower; 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 Warm River’s climate
What is the weather like in Warm River?
A typical July afternoon reaches 82°, a January night drops to 11°, and about 70 inches of snow falls in a normal winter. Colder January nights than 93% of U.S. towns; cooler July afternoons than 79% of U.S. towns.
How cold does it get in Warm River in winter?
January nights average 11°. About 190 nights a year reach 32° or below and 14 reach 0° or below. In the coldest January of the last 30 years the month averaged 13°.
How much snow does Warm River get?
About 70 inches in a normal winter at Ashton 1n, ID, most of it in January and December, with snow on the ground about 125 days a year.
How hot does it get in Warm River?
July, with a typical high of 82° and a low of 48°. About 9 days a year reach 90° (Ashton 1n, ID).
When is the first and last frost in Warm River?
In half of years the last spring frost (32°) comes by May 21 and the first fall frost by September 21, about 121 frost-free days, at Ashton 1n, ID.
What growing zone is Warm River in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −17°.
What is the best time of year to visit Warm River?
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 Warm River getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 52% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Warm River.
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.