St. Anthony, Idaho climate: Normal weather by month, frost dates and records
St. Anthony's normal year runs from 12°F January nights to 83°F July afternoons, with 14.8 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.2°C, January lows of −11°C, July highs of 29°C, 376 mm of precipitation a year.
- NOAA stationSaint Anthony
- Station IDUSC00108022
- Location43.95°N 111.68°W
- Elevation4,910 ft (1,497 m)
- Population4,093
On October 14, the normal high in St. Anthony is 59°F and the normal low 32°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 St. Anthony.
- Jan 28° 12°
- Feb 32° 14°
- Mar 44° 23°
- Apr 55° 31°
- May 65° 39°
- Jun 73° 45°
- Jul 83° 50°
- Aug 83° 49°
- Sep 73° 41°
- Oct 58° 32°
- Nov 41° 22°
- Dec 29° 13°
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 St. Anthony each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 12°F. The most precipitation falls in May (1.95 in), the least in August (0.62 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 28°F | 12°F | 19.7°F | 1.65 | 10 | <1 | 31 | 9 h 10 min |
| February | 32°F | 14°F | 23.2°F | 0.89 | 7 | <1 | 28 | 10 h 30 min |
| March | 44°F | 23°F | 33.3°F | 1.05 | 6 | <1 | 29 | 11 h 50 min |
| April | 55°F | 31°F | 43.0°F | 1.33 | 8 | <1 | 22 | 13 h 20 min |
| May | 65°F | 39°F | 52.0°F | 1.95 | 8 | <1 | 9 | 14 h 40 min |
| June | 73°F | 45°F | 59.3°F | 1.74 | 7 | <1 | 2 | 15 h 30 min |
| July | 83°F | 50°F | 66.9°F | 0.71 | 4 | 6 | <1 | 15 h 10 min |
| August | 83°F | 49°F | 65.7°F | 0.62 | 4 | 4 | 1 | 14 h |
| September | 73°F | 41°F | 56.8°F | 1.06 | 4 | <1 | 6 | 12 h 40 min |
| October | 58°F | 32°F | 44.6°F | 1.29 | 6 | <1 | 21 | 11 h 10 min |
| November | 41°F | 22°F | 31.5°F | 1.12 | 7 | <1 | 27 | 9 h 40 min |
| December | 29°F | 13°F | 21.1°F | 1.41 | 11 | <1 | 31 | 9 h |
| Year (annual) | 55°F | 31°F | 43.1°F | 14.82 | 82 | 10 | 206 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −2°C | −11°C | −6.8°C | 42 mm |
| February | 0°C | −10°C | −4.9°C | 23 mm |
| March | 6°C | −5°C | 0.7°C | 27 mm |
| April | 13°C | −1°C | 6.1°C | 34 mm |
| May | 18°C | 4°C | 11.1°C | 50 mm |
| June | 23°C | 7°C | 15.2°C | 44 mm |
| July | 29°C | 10°C | 19.4°C | 18 mm |
| August | 28°C | 9°C | 18.7°C | 16 mm |
| September | 23°C | 5°C | 13.8°C | 27 mm |
| October | 14°C | 0°C | 7.0°C | 33 mm |
| November | 5°C | −6°C | −0.3°C | 28 mm |
| December | −2°C | −10°C | −6.1°C | 36 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Ashton (14 miles away), gets 70 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00108022; 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 St. Anthony?
Normal highs sit between 65°F and 85°F in May, June, July, 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 USC00108022.
When is the last frost in St. Anthony?
In St. Anthony, the last spring frost (32°F) comes after May 17 in half of years and after June 10 in one year in ten; the first autumn frost comes before September 22 in half of years and before September 5 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 171 year in 10 after June 10; 9 in 10 after May 4
- First autumn frost, half of years before
- September 221 year in 10 before September 5; 9 in 10 before October 7
NOAA puts the median frost-free season at 126 days, and the season without a hard freeze (28°F) at 152 days.
A hard freeze (28°F) comes after May 4 in half of springs and before October 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts St. Anthony in zone 5a in ZIP code 83438, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, St. Anthony's NOAA station is in zone 5a: the coldest night of a typical year reaches −19°F (25 complete years).
Frost dates for every NOAA station in Idaho · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00108022; 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 St. Anthony?
In a normal year in St. Anthony, 10 days a year reach 90°F, 206 nights fall to 32°F or colder and 82 days bring measurable precipitation.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 206a normal year
- Days that stay below freezing
- 63high of 32°F or less
- Days with 0.01 inch of precipitation
- 82a normal year
The highest temperature in this station's record (since 1895) is 100°F, on June 26, 1988; the lowest is −40°F, on December 30, 1990.
The wettest calendar year on that record is 1995, with 22.80 in; the snowiest season is 2007–08, with 102.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00108022; records: ACIS (NOAA Regional Climate Centers), station USC00108022. Records use complete months only; a month missing more than three days is left out.
How sunny is St. Anthony?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around St. Anthony, 4.4 kWh per square metre a day. July is the sunniest month (89%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.8 |
| February | 66% | 2.7 |
| March | 69% | 4.0 |
| April | 70% | 5.2 |
| May | 74% | 6.3 |
| June | 82% | 7.3 |
| July | 89% | 7.6 |
| August | 87% | 6.5 |
| September | 83% | 5.0 |
| October | 74% | 3.2 |
| November | 66% | 1.9 |
| December | 58% | 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 St. Anthony need?
A normal year in St. Anthony brings 8,167 heating degree days, 52% more than the median U.S. place (5,373), and 215 cooling degree days, 76% 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 1,721 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,403 | 0 |
| February | 1,170 | 0 |
| March | 984 | 0 |
| April | 660 | 0 |
| May | 406 | 1 |
| June | 192 | 21 |
| July | 45 | 104 |
| August | 56 | 78 |
| September | 256 | 11 |
| October | 631 | 0 |
| November | 1,004 | 0 |
| December | 1,361 | 0 |
| Year (annual) | 8,167 | 215 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00108022. 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 St. Anthony been warmer than normal lately?
Over 52 complete years from 1943 to 2019, the station's annual mean temperature rose at a fitted 1.9°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 St. Anthony's climate compare?
St. Anthony is warmer than 15 of the other 84 places with their own NOAA record in Idaho, and wetter than 40. Across the 7,247 U.S. stations with normals, its annual mean of 43.1°F is warmer than 12%.
In the Köppen classification computed from these normals, St. Anthony 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 St. Anthony share this climate record?
2 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.
- Newdale, ID332 people · 6 mi SE
- Parker, ID298 people · 4 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 St. Anthony's climate
What is the coldest month in St. Anthony?
January, with a normal high of 28°F and a normal low of 12°F. The warmest is July (83°F by day, 50°F at night).
Does it snow in St. Anthony?
Yes. NOAA publishes no 1991-2020 snowfall normal for St. Anthony's NOAA station; the nearest record that keeps one, Ashton (14 miles away), records 70 inches of snow in a normal year.
What is the rainiest month in St. Anthony?
May, with 1.95 in of precipitation in a normal year; the driest is August with 0.62 in.
What plant hardiness zone is St. Anthony in?
The USDA's 2023 map puts St. Anthony in zone 5a in ZIP code 83438, the nearest ZIP area. By the same method at St. Anthony's NOAA station, the coldest night of a typical year reaches −19°F (25 years, 1991-2020): zone 5a.
How late can frost come in St. Anthony?
In half of years the last 32°F night comes after May 17; in one year in ten it comes after June 10. Waiting until June 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Sugar City, ID6 miles from this station, 42.7°F a year
- Rexburg, ID11 miles from this station, 44.0°F a year
- Rexburg BYU Idaho, ID11 miles from this station, 44.8°F a year
- Ashton, ID14 miles from this station, 43.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made