Tiber Dam, Montana climate: Climate normals at a NOAA weather station
Tiber Dam's normal year runs from 8°F January nights to 85°F July afternoons, with 10.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.0°C, January lows of −13°C, July highs of 30°C, 258 mm of precipitation a year.
- NOAA stationTiber Dam
- Station IDUSC00248233
- Location48.31°N 111.09°W
- Elevation2,850 ft (869 m)
On October 22, the normal high in Tiber Dam is 56°F and the normal low 30°F, and the chance of measurable rain or snow is 12%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Tiber Dam.
- Jan 31° 8°
- Feb 37° 12°
- Mar 48° 20°
- Apr 59° 30°
- May 69° 40°
- Jun 76° 48°
- Jul 85° 53°
- Aug 85° 51°
- Sep 74° 43°
- Oct 60° 32°
- Nov 44° 21°
- Dec 34° 12°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Tiber Dam each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 8°F. The most precipitation falls in June (2.25 in), the least in February (0.21 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 31°F | 8°F | 19.8°F | 0.36 | 3 | <1 | 30 | 8 h 40 min |
| February | 37°F | 12°F | 24.1°F | 0.21 | 2 | <1 | 27 | 10 h 10 min |
| March | 48°F | 20°F | 34.2°F | 0.34 | 3 | <1 | 28 | 11 h 50 min |
| April | 59°F | 30°F | 44.7°F | 0.98 | 6 | <1 | 18 | 13 h 40 min |
| May | 69°F | 40°F | 54.3°F | 1.38 | 7 | <1 | 5 | 15 h 10 min |
| June | 76°F | 48°F | 62.1°F | 2.25 | 8 | 2 | <1 | 16 h |
| July | 85°F | 53°F | 69.0°F | 1.07 | 4 | 11 | <1 | 15 h 40 min |
| August | 85°F | 51°F | 67.7°F | 1.07 | 4 | 9 | <1 | 14 h 20 min |
| September | 74°F | 43°F | 58.3°F | 0.91 | 4 | 2 | 2 | 12 h 40 min |
| October | 60°F | 32°F | 45.8°F | 0.75 | 4 | <1 | 16 | 11 h |
| November | 44°F | 21°F | 32.7°F | 0.45 | 3 | <1 | 25 | 9 h 20 min |
| December | 34°F | 12°F | 22.6°F | 0.38 | 3 | <1 | 30 | 8 h 20 min |
| Year (annual) | 59°F | 31°F | 44.6°F | 10.15 | 50 | 25 | 181 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 0°C | −13°C | −6.8°C | 9 mm |
| February | 3°C | −11°C | −4.4°C | 5 mm |
| March | 9°C | −7°C | 1.2°C | 9 mm |
| April | 15°C | −1°C | 7.1°C | 25 mm |
| May | 20°C | 4°C | 12.4°C | 35 mm |
| June | 25°C | 9°C | 16.7°C | 57 mm |
| July | 30°C | 12°C | 20.6°C | 27 mm |
| August | 29°C | 11°C | 19.8°C | 27 mm |
| September | 23°C | 6°C | 14.6°C | 23 mm |
| October | 15°C | 0°C | 7.7°C | 19 mm |
| November | 7°C | −6°C | 0.4°C | 11 mm |
| December | 1°C | −11°C | −5.2°C | 10 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Chester (15 miles away), gets 37 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00248233; 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.
Which months are mildest at Tiber Dam?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, August has the fewest days with rain (4).
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 USC00248233.
When is the last frost at Tiber Dam?
In Tiber Dam, the last spring frost (32°F) comes after May 16 in half of years and after May 30 in one year in ten; the first autumn frost comes before September 23 in half of years and before September 9 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 161 year in 10 after May 30; 9 in 10 after May 2
- First autumn frost, half of years before
- September 231 year in 10 before September 9; 9 in 10 before October 3
NOAA puts the median frost-free season at 129 days, and the season without a hard freeze (28°F) at 150 days.
A hard freeze (28°F) comes after May 3 in half of springs and before October 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Tiber Dam in zone 4a in ZIP code 59461, the nearest ZIP area.
Frost dates for every NOAA station in Montana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00248233; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 at Tiber Dam?
In a normal year in Tiber Dam, 25 days a year reach 90°F (1 of them 100°F or more), 181 nights fall to 32°F or colder and 50 days bring measurable precipitation.
- Days at 90°F or more
- 25a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 181a normal year
- Days that stay below freezing
- 41high of 32°F or less
- Days with 0.01 inch of precipitation
- 50a normal year
The highest temperature in this station's record (since 1952) is 107°F, on July 24, 2024; the lowest is −53°F, on January 20, 1954.
The wettest calendar year on that record is 1975, with 17.76 in; the snowiest season is 1964–65, with 45.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00248233; records: ACIS (NOAA Regional Climate Centers), station USC00248233. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Tiber Dam?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds at Tiber Dam, 3.9 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.3 |
| February | 69% | 2.3 |
| March | 70% | 3.5 |
| April | 72% | 4.9 |
| May | 73% | 5.9 |
| June | 78% | 6.6 |
| July | 87% | 7.1 |
| August | 85% | 5.8 |
| September | 79% | 4.2 |
| October | 73% | 2.6 |
| November | 67% | 1.5 |
| December | 62% | 1.0 |
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 many heating and cooling degree days does Tiber Dam record?
A normal year at Tiber Dam brings 7,753 heating degree days, 44% more than the median U.S. place (5,373), and 353 cooling degree days, 61% 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 2,051 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,400 | 0 |
| February | 1,144 | 0 |
| March | 955 | 0 |
| April | 609 | 0 |
| May | 341 | 7 |
| June | 128 | 41 |
| July | 30 | 154 |
| August | 45 | 130 |
| September | 222 | 21 |
| October | 596 | 1 |
| November | 969 | 0 |
| December | 1,316 | 0 |
| Year (annual) | 7,753 | 353 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00248233. 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.
Have recent years at Tiber Dam been warmer than normal?
2025 averaged 44.3°F, 0.3°F below the 1991-2020 normal of 44.6°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2025 | 44.3°F | −0.3°F | – |
Over 32 complete years from 1953 to 2025, the station's annual mean temperature rose at a fitted 1.6°F per century (+0.09°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00248233; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Tiber Dam's climate compare?
Tiber Dam is warmer than 83 of the 141 places with their own NOAA record in Montana, and wetter than 3. Across the 7,247 U.S. stations with normals, its annual mean of 44.6°F is warmer than 18%.
In the Köppen classification computed from these normals, Tiber Dam is BSk: cold semi-arid steppe. 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 Tiber Dam share this climate record?
Riverview Colony 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.
- Riverview Colony, MT212 people · 9 mi S
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 Tiber Dam's climate
What is the coldest month at Tiber Dam?
January, with a normal high of 31°F and a normal low of 8°F. The warmest is July (85°F by day, 53°F at night).
Does it snow at Tiber Dam?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Chester (15 miles away), records 37 inches of snow in a normal year.
What is the rainiest month at Tiber Dam?
June, with 2.25 in of precipitation in a normal year; the driest is February with 0.21 in.
What plant hardiness zone is Tiber Dam in?
The USDA's 2023 map puts Tiber Dam in zone 4a in ZIP code 59461, the nearest ZIP area.
How late can frost come at Tiber Dam?
In half of years the last 32°F night comes after May 16; in one year in ten it comes after May 30. Waiting until May 30 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Montana climateThe statewide normals and every place in the state
- Chester, MT15 miles from this station, 41.3°F a year
- Brady 27 ENE (The Knees), MT18 miles from this station, 45.1°F a year
- Rudyard (19 mi S), MT22 miles from this station, 40.6°F a year
- Joplin, MT22 miles from this station, 42.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made