Precipitation in Plains trails that of 93% of U.S. towns: 14 inches a year
The coldest hours of a January night bottom out at 21° on average. Its July heat outdoes that of 66% of U.S. towns. Compared with 1901–2000, the average now sits 1.1° higher. For walks and days out, May, June and September bring highs of 70–77°.
A year in Plains at a glance
Each month’s typical high and low, and what it brings.
What stands out about Plains’ climate
Compared with towns across the U.S., with Plains’ place in Montana beside it.
What a year in Plains 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 191 nights a year fall to 32° or below, and 6 to 0° or below. Frost and day counts come from NOAA’s station at Saint Regis 1 Ne, MT, 14 miles from the town’s center, 180 ft higher.
The 2023 USDA map puts Plains’ center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −6°. 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 15 inches of snow a winter
Snow, measured at Thompson Falls Ph, MT, falls mostly in December. Precipitation (rain plus melted snow) adds up to 14 inches a year; June is the wettest month and August the driest. Rain or snow falls on about 158 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Plains
97% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Saint Regis 1 Ne, MT.
Living with Plains’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 6a, and frost can come in any month. The longest frost-free stretch in half of years is about 101 days.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 0.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Plains from natural hazards, river flooding is the largest share (65%); heat waves, cold waves, winter storms and ice storms together are 15%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Plains and similar climates
TownRatings has no climate map of the towns around Plains yet.
Climates most like Plains’, 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 |
|---|---|---|---|---|
| Plains, MT | 21° | 88° | 14" | 15" |
| Cold Springs, NV | 23° | 88° | 13" | 17" |
| Eldorado at Santa Fe, NM | 19° | 87° | 13" | 20" |
| Show Low, AZ | 19° | 86° | 15" | 19" |
| Burley, ID | 21° | 89° | 10" | 21" |
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 Plains averaged 1.1° warmer than the 1900s. The biggest change is in January (+3.5°).
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 Plains compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Plains’ place among Montana’s.
Plains weather by month
Highs, lows and precipitation from NOAA’s grid at Plains’ center; snow, wet days and snow on the ground from Thompson Falls Ph, MT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 35° | 21° | 1.2" | 2.5" | 18 | 15° – 36° |
| February | 40° | 22° | 1.2" | 0.6" | 15 | 16° – 38° |
| March | 51° | 28° | 1.1" | 1.2" | 16 | 32° – 45° |
| April | 60° | 33° | 1.2" | 0.3" | 15 | 41° – 51° |
| May | 70° | 41° | 1.6" | 0.0" | 14 | 50° – 60° |
| June | 77° | 47° | 1.7" | 0.0" | 13 | 59° – 68° |
| July | 88° | 51° | 0.7" | 0.0" | 7 | 59° – 77° |
| August | 87° | 50° | 0.7" | 0.0" | 5 | 63° – 72° |
| September | 76° | 42° | 0.9" | 0.0" | 8 | 56° – 65° |
| October | 59° | 34° | 1.3" | 0.7" | 13 | 39° – 52° |
| November | 42° | 27° | 1.4" | 2.5" | 17 | 28° – 40° |
| December | 34° | 21° | 1.5" | 7.5" | 17 | 21° – 33° |
| Year | 60° | 35° | 14.4" | 15.3" | 158 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 15° to 36°. August is the most reliable, staying within 9°.
Where Plains’ 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 Plains’ center.
- Snow: Thompson Falls Ph, MT.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Saint Regis 1 Ne, MT, 14 miles from the town’s center, 180 ft higher; 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 Plains’ climate
What is the weather like in Plains?
A typical July afternoon reaches 88°, a January night drops to 21°, and about 15 inches of snow falls in a normal winter. Colder January nights than 55% of U.S. towns; hotter July afternoons than 66% of U.S. towns.
How cold does it get in Plains in winter?
January nights average 21°. About 191 nights a year reach 32° or below and 6 reach 0° or below. In the coldest January of the last 30 years the month averaged 15°.
How much snow does Plains get?
About 15 inches in a normal winter at Thompson Falls Ph, MT, most of it in December.
How hot does it get in Plains?
July, with a typical high of 88° and a low of 51°. About 29 days a year reach 90° and 1 reach 100° (Saint Regis 1 Ne, MT).
When is the first and last frost in Plains?
There is no reliable frost-free season: at Saint Regis 1 Ne, MT, every month has nights at 32° or below, about 191 a year. In half of years the longest stretch without a freeze is about 101 days.
What growing zone is Plains in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −6°.
What is the best time of year to visit Plains?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Plains 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 Plains.
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.