Thompson Falls, Montana climate: Normal weather by month, frost dates and records
Thompson Falls's normal year runs from 25°F December nights to 86°F July afternoons, with 22.1 inches of precipitation and 15 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.7°C, December lows of −4°C, July highs of 30°C, 560 mm of precipitation a year.
- NOAA stationThompson Falls Powerhouse
- Station IDUSC00248211
- Location47.59°N 115.36°W
- Elevation2,380 ft (725 m)
- Population1,526
On October 14, the normal high in Thompson Falls is 59°F and the normal low 36°F, and the chance of measurable rain or snow is 42%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Thompson Falls.
- Jan 34° 24°
- Feb 40° 25°
- Mar 49° 29°
- Apr 58° 34°
- May 68° 41°
- Jun 75° 48°
- Jul 86° 53°
- Aug 86° 52°
- Sep 75° 44°
- Oct 58° 36°
- Nov 41° 29°
- Dec 33° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Thompson Falls each month?
July is the warmest month, with normal highs of 86°F; December the coldest, with normal lows of 25°F. The most precipitation falls in November (2.64 in), the least in July (0.88 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 34°F | 24°F | 29.1°F | 2.34 | 2.5 | 18 | <1 | 28 | 8 h 50 min |
| February | 40°F | 25°F | 32.3°F | 1.94 | 0.6 | 15 | <1 | 25 | 10 h 10 min |
| March | 49°F | 29°F | 39.4°F | 1.99 | 1.2 | 16 | <1 | 22 | 11 h 50 min |
| April | 58°F | 34°F | 46.3°F | 1.65 | 0.3 | 15 | <1 | 12 | 13 h 30 min |
| May | 68°F | 41°F | 54.9°F | 2.09 | 0.0 | 14 | 1 | 3 | 15 h 10 min |
| June | 75°F | 48°F | 61.1°F | 2.19 | 0.0 | 13 | 3 | <1 | 16 h |
| July | 86°F | 53°F | 69.5°F | 0.88 | 0.0 | 7 | 15 | <1 | 15 h 40 min |
| August | 86°F | 52°F | 68.8°F | 0.89 | 0.0 | 5 | 15 | <1 | 14 h 20 min |
| September | 75°F | 44°F | 59.8°F | 0.97 | 0.0 | 8 | 4 | 1 | 12 h 40 min |
| October | 58°F | 36°F | 46.9°F | 2.16 | 0.7 | 13 | <1 | 10 | 11 h |
| November | 41°F | 29°F | 35.3°F | 2.64 | 2.5 | 17 | <1 | 20 | 9 h 20 min |
| December | 33°F | 25°F | 28.7°F | 2.31 | 7.5 | 17 | <1 | 28 | 8 h 30 min |
| Year (annual) | 59°F | 37°F | 47.7°F | 22.05 | 15.3 | 158 | 39 | 148 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −4°C | −1.6°C | 59 mm | 6 cm |
| February | 4°C | −4°C | 0.2°C | 49 mm | 2 cm |
| March | 10°C | −1°C | 4.1°C | 51 mm | 3 cm |
| April | 15°C | 1°C | 7.9°C | 42 mm | 1 cm |
| May | 20°C | 5°C | 12.7°C | 53 mm | 0 cm |
| June | 24°C | 9°C | 16.2°C | 56 mm | 0 cm |
| July | 30°C | 12°C | 20.8°C | 22 mm | 0 cm |
| August | 30°C | 11°C | 20.4°C | 23 mm | 0 cm |
| September | 24°C | 7°C | 15.4°C | 25 mm | 0 cm |
| October | 14°C | 2°C | 8.3°C | 55 mm | 2 cm |
| November | 5°C | −1°C | 1.8°C | 67 mm | 6 cm |
| December | 0°C | −4°C | −1.8°C | 59 mm | 19 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00248211; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Thompson Falls?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (8).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00248211.
When is the last frost in Thompson Falls?
In Thompson Falls, the last spring frost (32°F) comes after May 7 in half of years and after May 19 in one year in ten; the first autumn frost comes before October 4 in half of years and before September 21 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 71 year in 10 after May 19; 9 in 10 after April 25
- First autumn frost, half of years before
- October 41 year in 10 before September 21; 9 in 10 before October 19
NOAA puts the median frost-free season at 150 days, and the season without a hard freeze (28°F) at 181 days.
A hard freeze (28°F) comes after April 22 in half of springs and before October 18 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Thompson Falls in zone 6a in ZIP code 59873, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Thompson Falls's NOAA station is in zone 6b: the coldest night of a typical year reaches −2°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Montana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00248211; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Thompson Falls?
In a normal year in Thompson Falls, 39 days a year reach 90°F (4 of them 100°F or more), 148 nights fall to 32°F or colder and 158 days bring measurable precipitation.
- Days at 90°F or more
- 39a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 148a normal year
- Days that stay below freezing
- 22high of 32°F or less
- Days with 0.01 inch of precipitation
- 158a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1956) is 107°F, on August 4, 1961; the lowest is −25°F, on December 30, 1968.
The wettest calendar year on that record is 1961, with 30.08 in; the snowiest season is 1977–78, with 99.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00248211; records: ACIS (NOAA Regional Climate Centers), station USC00248211. Records use complete months only; a month missing more than three days is left out.
How sunny is Thompson Falls?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Thompson Falls, 3.7 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (51%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 54% | 1.1 |
| February | 60% | 2.0 |
| March | 62% | 3.2 |
| April | 66% | 4.5 |
| May | 69% | 5.6 |
| June | 71% | 6.2 |
| July | 87% | 7.3 |
| August | 84% | 6.0 |
| September | 77% | 4.2 |
| October | 66% | 2.5 |
| November | 54% | 1.3 |
| December | 51% | 0.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Thompson Falls need?
A normal year in Thompson Falls brings 6,671 heating degree days, 24% more than the median U.S. place (5,373), and 391 cooling degree days, 57% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,106 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,114 | 0 |
| February | 914 | 0 |
| March | 794 | 0 |
| April | 561 | 0 |
| May | 320 | 7 |
| June | 152 | 36 |
| July | 30 | 171 |
| August | 31 | 150 |
| September | 181 | 26 |
| October | 560 | 0 |
| November | 889 | 0 |
| December | 1,125 | 0 |
| Year (annual) | 6,671 | 391 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00248211. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Thompson Falls been warmer than normal lately?
2025 averaged 49.7°F, 2.0°F above the 1991-2020 normal of 47.7°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.0°F | +1.3°F | 21.37 | – |
| 2022 | 46.6°F | −1.1°F | 23.19 | – |
| 2023 | 48.7°F | +1.0°F | 14.50 | 9.7 |
| 2024 | 49.1°F | +1.4°F | 18.33 | 19.2 |
| 2025 | 49.7°F | +2.0°F | 22.48 | – |
Over 48 complete years from 1957 to 2025, the station's annual mean temperature rose at a fitted 4.2°F per century (+0.23°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00248211; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Thompson Falls's climate compare?
Thompson Falls is warmer than 134 of the other 140 places with their own NOAA record in Montana, and wetter than 120. Across the 7,247 U.S. stations with normals, its annual mean of 47.7°F is warmer than 31%.
In the Köppen classification computed from these normals, Thompson Falls is Dfb: continental, no dry season, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Thompson Falls share this climate record?
Belknap has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Belknap, MT0 people · 5 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Thompson Falls's climate
What is the coldest month in Thompson Falls?
December, with a normal high of 33°F and a normal low of 25°F. The warmest is July (86°F by day, 53°F at night).
Does it snow in Thompson Falls?
Yes: 15 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in December (7.5 inches).
What is the rainiest month in Thompson Falls?
November, with 2.64 in of precipitation in a normal year; the driest is July with 0.88 in.
What plant hardiness zone is Thompson Falls in?
The USDA's 2023 map puts Thompson Falls in zone 6a in ZIP code 59873, the nearest ZIP area. By the same method at Thompson Falls's NOAA station, the coldest night of a typical year reaches −2°F (30 years, 1991-2020): zone 6b.
How late can frost come in Thompson Falls?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 19. Waiting until May 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Montana climateThe statewide normals and every place in the state
- Haugan, MT14 miles from this station, 42.2°F a year
- Mullan, ID16 miles from this station, 38.6°F a year
- Trout Creek, MT22 miles from this station, 46.1°F a year
- St. Regis, MT24 miles from this station, 46.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made