Blackfoot, Idaho climate: Normal weather by month, frost dates and records
Blackfoot's normal year runs from 17°F January nights to 87°F July afternoons, with 12.1 inches of precipitation and 15 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.4°C, January lows of −8°C, July highs of 31°C, 306 mm of precipitation a year.
- NOAA stationBlackfoot Fire Dept
- Station IDUSC00100915
- Location43.19°N 112.35°W
- Elevation4,499 ft (1,371 m)
- Population13,224
On October 14, the normal high in Blackfoot is 61°F and the normal low 36°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Blackfoot.
- Jan 31° 17°
- Feb 37° 21°
- Mar 49° 29°
- Apr 57° 35°
- May 68° 43°
- Jun 77° 50°
- Jul 87° 56°
- Aug 86° 54°
- Sep 75° 46°
- Oct 61° 35°
- Nov 45° 26°
- Dec 32° 18°
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 Blackfoot each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 17°F. The most precipitation falls in May (1.75 in), the least in July (0.50 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 17°F | 24.0°F | 0.99 | 6.0 | 8 | <1 | 30 | 9 h 20 min |
| February | 37°F | 21°F | 28.8°F | 0.73 | 2.2 | 7 | <1 | 26 | 10 h 30 min |
| March | 49°F | 29°F | 39.0°F | 1.10 | 0.3 | 7 | <1 | 22 | 11 h 50 min |
| April | 57°F | 35°F | 46.1°F | 1.40 | 0.7 | 9 | <1 | 13 | 13 h 20 min |
| May | 68°F | 43°F | 55.2°F | 1.75 | 0.0 | 8 | <1 | 3 | 14 h 40 min |
| June | 77°F | 50°F | 63.2°F | 1.03 | 0.0 | 6 | 2 | <1 | 15 h 20 min |
| July | 87°F | 56°F | 71.4°F | 0.50 | 0.0 | 3 | 12 | <1 | 15 h 10 min |
| August | 86°F | 54°F | 70.1°F | 0.60 | 0.0 | 3 | 11 | <1 | 14 h |
| September | 75°F | 46°F | 60.6°F | 0.97 | 0.0 | 4 | 1 | 1 | 12 h 30 min |
| October | 61°F | 35°F | 47.8°F | 1.12 | 0.8 | 6 | <1 | 13 | 11 h 10 min |
| November | 45°F | 26°F | 35.1°F | 0.75 | 1.4 | 5 | <1 | 25 | 9 h 50 min |
| December | 32°F | 18°F | 24.8°F | 1.11 | 3.3 | 8 | <1 | 29 | 9 h |
| Year (annual) | 59°F | 36°F | 47.2°F | 12.05 | 14.7 | 74 | 26 | 162 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −8°C | −4.4°C | 25 mm | 15 cm |
| February | 3°C | −6°C | −1.8°C | 19 mm | 6 cm |
| March | 9°C | −2°C | 3.9°C | 28 mm | 1 cm |
| April | 14°C | 2°C | 7.8°C | 36 mm | 2 cm |
| May | 20°C | 6°C | 12.9°C | 44 mm | 0 cm |
| June | 25°C | 10°C | 17.3°C | 26 mm | 0 cm |
| July | 31°C | 13°C | 21.9°C | 13 mm | 0 cm |
| August | 30°C | 12°C | 21.2°C | 15 mm | 0 cm |
| September | 24°C | 8°C | 15.9°C | 25 mm | 0 cm |
| October | 16°C | 2°C | 8.8°C | 28 mm | 2 cm |
| November | 7°C | −4°C | 1.7°C | 19 mm | 4 cm |
| December | 0°C | −8°C | −4.0°C | 28 mm | 8 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00100915; 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 Blackfoot?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September 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 USC00100915.
When is the last frost in Blackfoot?
In Blackfoot, the last spring frost (32°F) comes after May 5 in half of years and after May 22 in one year in ten; the first autumn frost comes before October 3 in half of years and before September 16 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 51 year in 10 after May 22; 9 in 10 after April 23
- First autumn frost, half of years before
- October 31 year in 10 before September 16; 9 in 10 before October 18
NOAA puts the median frost-free season at 149 days, and the season without a hard freeze (28°F) at 176 days.
A hard freeze (28°F) comes after April 22 in half of springs and before October 16 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Blackfoot in zone 5b in ZIP code 83221, the nearest ZIP area.
Frost dates for every NOAA station in Idaho · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00100915; 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 in Blackfoot?
In a normal year in Blackfoot, 26 days a year reach 90°F (1 of them 100°F or more), 162 nights fall to 32°F or colder and 74 days bring measurable precipitation.
- Days at 90°F or more
- 26a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 162a normal year
- Days that stay below freezing
- 41high of 32°F or less
- Days with 0.01 inch of precipitation
- 74a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1895) is 108°F, on June 21, 1900; the lowest is −40°F, on January 21, 1937.
The wettest calendar year on that record is 1963, with 23.09 in; the snowiest season is 1915–16, with 73.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00100915; records: ACIS (NOAA Regional Climate Centers), station USC00100915. Records use complete months only; a month missing more than three days is left out.
How sunny is Blackfoot?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Blackfoot, 4.5 kWh per square metre a day. July is the sunniest month (90%) and December the cloudiest (60%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 1.8 |
| February | 68% | 2.7 |
| March | 73% | 4.1 |
| April | 76% | 5.5 |
| May | 79% | 6.6 |
| June | 85% | 7.5 |
| July | 90% | 7.6 |
| August | 89% | 6.6 |
| September | 87% | 5.1 |
| October | 80% | 3.5 |
| November | 72% | 2.1 |
| December | 60% | 1.4 |
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 Blackfoot need?
A normal year in Blackfoot brings 6,990 heating degree days, 30% more than the median U.S. place (5,373), and 519 cooling degree days, 43% 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 2,337 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,271 | 0 |
| February | 1,015 | 0 |
| March | 808 | 0 |
| April | 569 | 0 |
| May | 315 | 12 |
| June | 120 | 68 |
| July | 18 | 218 |
| August | 23 | 179 |
| September | 174 | 41 |
| October | 536 | 1 |
| November | 896 | 0 |
| December | 1,246 | 0 |
| Year (annual) | 6,990 | 519 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00100915. 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 Blackfoot been warmer than normal lately?
Over 59 complete years from 1897 to 2021, the station's annual mean temperature rose at a fitted 2.0°F per century (+0.11°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Blackfoot's climate compare?
Blackfoot is warmer than 51 of the other 84 places with their own NOAA record in Idaho, and wetter than 31. Across the 7,247 U.S. stations with normals, its annual mean of 47.2°F is warmer than 29%.
In the Köppen classification computed from these normals, Blackfoot 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 Blackfoot share this climate record?
6 places have no NOAA station with 1991-2020 normals of their 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.
- Moreland, ID1,386 people · 5 mi W
- Groveland, ID1,204 people · 3 mi NW
- Riverside, ID1,126 people · 5 mi W
- Firth, ID542 people · 11 mi NE
- Basalt, ID374 people · 12 mi NE
- Rockford, ID305 people · 9 mi W
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 Blackfoot's climate
What is the coldest month in Blackfoot?
January, with a normal high of 31°F and a normal low of 17°F. The warmest is July (87°F by day, 56°F at night).
Does it snow in Blackfoot?
Yes: 15 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (6.0 inches).
What is the rainiest month in Blackfoot?
May, with 1.75 in of precipitation in a normal year; the driest is July with 0.50 in.
What plant hardiness zone is Blackfoot in?
The USDA's 2023 map puts Blackfoot in zone 5b in ZIP code 83221, the nearest ZIP area.
How late can frost come in Blackfoot?
In half of years the last 32°F night comes after May 5; in one year in ten it comes after May 22. Waiting until May 22 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Fort Hall, ID11 miles from this station, 45.4°F a year
- Pocatello, ID22 miles from this station, 47.0°F a year
- Idaho Falls, ID27 miles from this station, 44.2°F a year
- Idaho Falls - Kifi, ID28 miles from this station, 46.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made