Island Park, Idaho climate: Normal weather by month, frost dates and records
Island Park's normal year runs from 6°F December nights to 77°F July afternoons, with 28.8 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 2.7°C, December lows of −14°C, July highs of 25°C, 732 mm of precipitation a year.
- NOAA stationIsland Park
- Station IDUSC00104598
- Location44.42°N 111.37°W
- Elevation6,290 ft (1,917 m)
- Population191
On October 23, the normal high in Island Park is 47°F and the normal low 22°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Island Park.
- Jan 27° 6°
- Feb 30° 8°
- Mar 39° 15°
- Apr 47° 23°
- May 59° 32°
- Jun 67° 38°
- Jul 77° 43°
- Aug 77° 40°
- Sep 68° 32°
- Oct 51° 24°
- Nov 36° 14°
- Dec 26° 6°
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 Island Park each month?
July is the warmest month, with normal highs of 77°F; December the coldest, with normal lows of 6°F. The most precipitation falls in December (4.01 in), the least in August (1.14 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 27°F | 6°F | 16.2°F | 3.53 | – | <1 | 31 | 9 h 10 min |
| February | 30°F | 8°F | 18.6°F | 2.64 | – | <1 | 28 | 10 h 30 min |
| March | 39°F | 15°F | 26.5°F | 2.05 | – | <1 | 30 | 11 h 50 min |
| April | 47°F | 23°F | 35.3°F | 2.37 | – | <1 | 28 | 13 h 20 min |
| May | 59°F | 32°F | 45.4°F | 2.99 | – | <1 | 17 | 14 h 50 min |
| June | 67°F | 38°F | 52.6°F | 2.63 | – | <1 | 6 | 15 h 30 min |
| July | 77°F | 43°F | 60.0°F | 1.17 | – | 2 | 1 | 15 h 10 min |
| August | 77°F | 40°F | 58.6°F | 1.14 | – | 1 | 3 | 14 h 10 min |
| September | 68°F | 32°F | 50.1°F | 1.66 | – | <1 | 16 | 12 h 40 min |
| October | 51°F | 24°F | 37.7°F | 2.09 | – | <1 | 27 | 11 h |
| November | 36°F | 14°F | 25.0°F | 2.54 | – | <1 | 29 | 9 h 40 min |
| December | 26°F | 6°F | 16.0°F | 4.01 | – | <1 | 31 | 8 h 50 min |
| Year (annual) | 50°F | 23°F | 36.8°F | 28.82 | – | 3 | 247 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −3°C | −14°C | −8.8°C | 90 mm |
| February | −1°C | −14°C | −7.4°C | 67 mm |
| March | 4°C | −10°C | −3.1°C | 52 mm |
| April | 9°C | −5°C | 1.8°C | 60 mm |
| May | 15°C | 0°C | 7.4°C | 76 mm |
| June | 20°C | 3°C | 11.4°C | 67 mm |
| July | 25°C | 6°C | 15.6°C | 30 mm |
| August | 25°C | 4°C | 14.8°C | 29 mm |
| September | 20°C | 0°C | 10.1°C | 42 mm |
| October | 11°C | −4°C | 3.2°C | 53 mm |
| November | 2°C | −10°C | −3.9°C | 65 mm |
| December | −4°C | −14°C | −8.9°C | 102 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Ashton (24 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 USC00104598; 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 Island Park?
Normal highs sit between 65°F and 85°F in June, July, August and September.
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 USC00104598.
How hot and how cold does it get in Island Park?
In a normal year in Island Park, 3 days a year reach 90°F and 247 nights fall to 32°F or colder.
- Days at 90°F or more
- 3a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 247a normal year
- Days that stay below freezing
- 77high of 32°F or less
The highest temperature in this station's record (since 1937) is 97°F, on July 29, 1996; the lowest is −51°F, on December 17, 1964.
The wettest calendar year on that record is 1970, with 42.90 in; the snowiest season is 1951–52, with 355.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00104598; records: ACIS (NOAA Regional Climate Centers), station USC00104598. Records use complete months only; a month missing more than three days is left out.
How sunny is Island Park?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Island Park, 4.2 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 60% | 1.6 |
| February | 65% | 2.6 |
| March | 65% | 3.7 |
| April | 68% | 5.0 |
| May | 70% | 5.9 |
| June | 77% | 6.9 |
| July | 87% | 7.5 |
| August | 86% | 6.3 |
| September | 81% | 4.8 |
| October | 71% | 3.0 |
| November | 62% | 1.8 |
| December | 56% | 1.3 |
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 Island Park need?
A normal year in Island Park brings 10,272 heating degree days, 91% more than the median U.S. place (5,373), and 23 cooling degree days, 97% fewer than the median (908). Ten months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 833 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,513 | 0 |
| February | 1,299 | 0 |
| March | 1,192 | 0 |
| April | 893 | 0 |
| May | 609 | 0 |
| June | 375 | 1 |
| July | 170 | 14 |
| August | 206 | 8 |
| September | 448 | 1 |
| October | 846 | 0 |
| November | 1,202 | 0 |
| December | 1,520 | 0 |
| Year (annual) | 10,272 | 23 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00104598. 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 Island Park been warmer than normal lately?
2022 averaged 35.4°F, 1.4°F below the 1991-2020 normal of 36.8°F. 1 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 39.1°F | +2.3°F | 29.22 |
| 2022 | 35.4°F | −1.4°F | 25.40 |
Over 55 complete years from 1938 to 2025, the station's annual mean temperature rose at a fitted 1.8°F per century (+0.10°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00104598; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Island Park's climate compare?
Island Park is warmer than 0 of the other 84 places with their own NOAA record in Idaho, and wetter than 72. Across the 7,247 U.S. stations with normals, its annual mean of 36.8°F is warmer than 2%.
In the Köppen classification computed from these normals, Island Park is Dsb: continental, dry-summer, 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 Island Park's climate
What is the coldest month in Island Park?
December, with a normal high of 26°F and a normal low of 6°F. The warmest is July (77°F by day, 43°F at night).
Does it snow in Island Park?
Yes. NOAA publishes no 1991-2020 snowfall normal for Island Park's NOAA station; the nearest record that keeps one, Ashton (24 miles away), records 70 inches of snow in a normal year.
What is the rainiest month in Island Park?
December, with 4.01 in of precipitation in a normal year; the driest is August with 1.14 in.
What plant hardiness zone is Island Park in?
The USDA's 2023 map puts Island Park in zone 4a in ZIP code 83433. By the same method at Island Park's NOAA station, the coldest night of a typical year reaches −28°F (20 years, 1991-2020): zone 4a.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- West Yellowstone, MT22 miles from this station, 35.2°F a year
- Ashton, ID24 miles from this station, 43.4°F a year
- Lakeview, MT25 miles from this station, 36.4°F a year
- Old Faithful, WY27 miles from this station, 34.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made