Riggins, Idaho climate: Normal weather by month, frost dates and records
Riggins's normal year runs from 25°F December nights to 90°F July afternoons, with 17.4 inches of precipitation and 7 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.1°C, December lows of −4°C, July highs of 32°C, 443 mm of precipitation a year.
- NOAA stationRiggins
- Station IDUSC00107706
- Location45.35°N 116.39°W
- Elevation2,056 ft (627 m)
- Population394
On October 22, the normal high in Riggins is 60°F and the normal low 35°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Riggins.
- Jan 41° 25°
- Feb 46° 26°
- Mar 55° 30°
- Apr 62° 35°
- May 71° 41°
- Jun 78° 47°
- Jul 90° 52°
- Aug 90° 52°
- Sep 80° 45°
- Oct 64° 36°
- Nov 48° 29°
- Dec 40° 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 Riggins each month?
July is the warmest month, with normal highs of 90°F; December the coldest, with normal lows of 25°F. The most precipitation falls in May (2.17 in), the least in August (0.73 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 41°F | 25°F | 32.6°F | 1.31 | 2.1 | 12 | <1 | 21 | 9 h 10 min |
| February | 46°F | 26°F | 35.9°F | 1.40 | 2.3 | 10 | <1 | 18 | 10 h 20 min |
| March | 55°F | 30°F | 42.6°F | 1.81 | 0.1 | 13 | <1 | 12 | 11 h 50 min |
| April | 62°F | 35°F | 48.4°F | 2.03 | 0.0 | 14 | <1 | 4 | 13 h 30 min |
| May | 71°F | 41°F | 55.9°F | 2.17 | 0.0 | 13 | 2 | <1 | 14 h 50 min |
| June | 78°F | 47°F | 62.3°F | 1.72 | 0.0 | 10 | 6 | <1 | 15 h 40 min |
| July | 90°F | 52°F | 71.1°F | 0.76 | 0.0 | 5 | 20 | <1 | 15 h 20 min |
| August | 90°F | 52°F | 71.0°F | 0.73 | 0.0 | 4 | 20 | <1 | 14 h 10 min |
| September | 80°F | 45°F | 62.4°F | 1.16 | 0.0 | 5 | 8 | <1 | 12 h 40 min |
| October | 64°F | 36°F | 49.9°F | 1.48 | 0.0 | 8 | <1 | 4 | 11 h |
| November | 48°F | 29°F | 38.7°F | 1.43 | 0.6 | 12 | <1 | 13 | 9 h 30 min |
| December | 40°F | 25°F | 32.0°F | 1.44 | 2.0 | 12 | <1 | 21 | 8 h 50 min |
| Year (annual) | 64°F | 37°F | 50.2°F | 17.44 | 7.1 | 116 | 57 | 92 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −4°C | 0.3°C | 33 mm | 5 cm |
| February | 8°C | −4°C | 2.2°C | 36 mm | 6 cm |
| March | 13°C | −1°C | 5.9°C | 46 mm | 0 cm |
| April | 17°C | 1°C | 9.1°C | 52 mm | 0 cm |
| May | 22°C | 5°C | 13.3°C | 55 mm | 0 cm |
| June | 25°C | 8°C | 16.8°C | 44 mm | 0 cm |
| July | 32°C | 11°C | 21.7°C | 19 mm | 0 cm |
| August | 32°C | 11°C | 21.7°C | 19 mm | 0 cm |
| September | 26°C | 7°C | 16.9°C | 29 mm | 0 cm |
| October | 18°C | 2°C | 9.9°C | 38 mm | 0 cm |
| November | 9°C | −2°C | 3.7°C | 36 mm | 2 cm |
| December | 4°C | −4°C | 0.0°C | 37 mm | 5 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00107706; 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 Riggins?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (5).
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 USC00107706.
When is the last frost in Riggins?
In Riggins, the last spring frost (32°F) comes after May 6 in half of years and after May 26 in one year in ten; the first autumn frost comes before October 9 in half of years and before September 24 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 61 year in 10 after May 26; 9 in 10 after April 23
- First autumn frost, half of years before
- October 91 year in 10 before September 24; 9 in 10 before October 26
NOAA puts the median frost-free season at 155 days, and the season without a hard freeze (28°F) at 185 days.
A hard freeze (28°F) comes after April 18 in half of springs and before October 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Riggins in zone 6b in ZIP code 83549, 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 USC00107706; 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 Riggins?
In a normal year in Riggins, 57 days a year reach 90°F (14 of them 100°F or more), 92 nights fall to 32°F or colder and 116 days bring measurable precipitation.
- Days at 90°F or more
- 57a normal year
- Days at 100°F or more
- 14a normal year
- Nights at 32°F or colder
- 92a normal year
- Days that stay below freezing
- 5high of 32°F or less
- Days with 0.01 inch of precipitation
- 116a normal year
- Days with 1 inch of snow or more
- 3a normal year
The highest temperature in this station's record (since 1896) is 115°F, on August 20, 1967; the lowest is −10°F, on January 27, 1957.
The wettest calendar year on that record is 2020, with 21.99 in; the snowiest season is 2018–19, with 31.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00107706; records: ACIS (NOAA Regional Climate Centers), station USC00107706. Records use complete months only; a month missing more than three days is left out.
How sunny is Riggins?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Riggins, 4.1 kWh per square metre a day. July is the sunniest month (90%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 62% | 1.5 |
| February | 65% | 2.4 |
| March | 64% | 3.4 |
| April | 67% | 4.7 |
| May | 71% | 5.9 |
| June | 77% | 6.8 |
| July | 90% | 7.6 |
| August | 89% | 6.4 |
| September | 83% | 4.7 |
| October | 73% | 2.9 |
| November | 62% | 1.6 |
| December | 56% | 1.1 |
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 Riggins need?
A normal year in Riggins brings 5,907 heating degree days, 10% more than the median U.S. place (5,373), and 552 cooling degree days, 39% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,443 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,006 | 0 |
| February | 815 | 0 |
| March | 695 | 0 |
| April | 500 | 1 |
| May | 297 | 15 |
| June | 133 | 52 |
| July | 24 | 213 |
| August | 21 | 209 |
| September | 137 | 61 |
| October | 471 | 3 |
| November | 788 | 0 |
| December | 1,021 | 0 |
| Year (annual) | 5,907 | 552 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00107706. 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 Riggins been warmer than normal lately?
2025 averaged 52.9°F, 2.7°F above the 1991-2020 normal of 50.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 51.9°F | +1.7°F | 17.02 | 21.1 |
| 2022 | 49.8°F | −0.4°F | 19.45 | 17.6 |
| 2023 | 51.1°F | +0.9°F | 17.67 | 10.0 |
| 2024 | 52.1°F | +1.9°F | 20.28 | 5.0 |
| 2025 | 52.9°F | +2.7°F | 18.93 | 16.0 |
Over 42 complete years from 1897 to 2025, the station's annual mean temperature rose at a fitted 0.0°F per century (+0.00°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00107706; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Riggins's climate compare?
Riggins is warmer than 67 of the other 84 places with their own NOAA record in Idaho, and wetter than 47. Across the 7,247 U.S. stations with normals, its annual mean of 50.2°F is warmer than 41%.
In the Köppen classification computed from these normals, Riggins is Cfb: temperate, 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.
Questions about Riggins's climate
What is the coldest month in Riggins?
December, with a normal high of 40°F and a normal low of 25°F. The warmest is July (90°F by day, 52°F at night).
Does it snow in Riggins?
Yes: 7 inches in a normal year, falling on 4 days with 0.1 inch or more, the most in February (2.3 inches).
What is the rainiest month in Riggins?
May, with 2.17 in of precipitation in a normal year; the driest is August with 0.73 in.
What plant hardiness zone is Riggins in?
The USDA's 2023 map puts Riggins in zone 6b in ZIP code 83549, the nearest ZIP area.
How late can frost come in Riggins?
In half of years the last 32°F night comes after May 6; in one year in ten it comes after May 26. Waiting until May 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- New Meadows, ID27 miles from this station, 41.4°F a year
- McCall, ID35 miles from this station, 41.5°F a year
- Warren, ID35 miles from this station, 38.3°F a year
- Joseph, OR40 miles from this station, 44.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made