Deer Flat Dam, Idaho climate: Climate normals at a NOAA weather station
Deer Flat Dam's normal year runs from 24°F December nights to 90°F July afternoons, with 10.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.4°C, December lows of −4°C, July highs of 32°C, 254 mm of precipitation a year.
- NOAA stationDeer Flat Dam
- Station IDUSC00102444
- Location43.58°N 116.75°W
- Elevation2,510 ft (765 m)
On October 23, the normal high in Deer Flat Dam is 63°F and the normal low 37°F, and the chance of measurable rain or snow is 16%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Deer Flat Dam.
- Jan 40° 25°
- Feb 47° 27°
- Mar 58° 34°
- Apr 65° 38°
- May 73° 46°
- Jun 81° 52°
- Jul 90° 59°
- Aug 89° 57°
- Sep 80° 49°
- Oct 66° 39°
- Nov 50° 31°
- Dec 40° 24°
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 Deer Flat Dam each month?
July is the warmest month, with normal highs of 90°F; December the coldest, with normal lows of 24°F. The most precipitation falls in January (1.22 in), the least in August (0.19 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 40°F | 25°F | 32.2°F | 1.22 | 10 | <1 | 25 | 9 h 20 min |
| February | 47°F | 27°F | 37.4°F | 0.99 | 6 | <1 | 20 | 10 h 30 min |
| March | 58°F | 34°F | 46.1°F | 1.10 | 8 | <1 | 11 | 11 h 50 min |
| April | 65°F | 38°F | 51.4°F | 1.06 | 8 | <1 | 5 | 13 h 20 min |
| May | 73°F | 46°F | 59.5°F | 1.15 | 8 | 1 | <1 | 14 h 40 min |
| June | 81°F | 52°F | 66.5°F | 0.70 | 6 | 4 | <1 | 15 h 20 min |
| July | 90°F | 59°F | 74.6°F | 0.29 | 2 | 17 | <1 | 15 h 10 min |
| August | 89°F | 57°F | 73.1°F | 0.19 | 2 | 16 | <1 | 14 h |
| September | 80°F | 49°F | 64.5°F | 0.37 | 2 | 3 | <1 | 12 h 30 min |
| October | 66°F | 39°F | 52.8°F | 0.75 | 5 | <1 | 4 | 11 h 10 min |
| November | 50°F | 31°F | 40.4°F | 1.07 | 7 | <1 | 17 | 9 h 40 min |
| December | 40°F | 24°F | 32.0°F | 1.11 | 9 | <1 | 24 | 9 h |
| Year (annual) | 65°F | 40°F | 52.5°F | 10.00 | 72 | 41 | 106 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | −4°C | 0.1°C | 31 mm |
| February | 9°C | −3°C | 3.0°C | 25 mm |
| March | 15°C | 1°C | 7.8°C | 28 mm |
| April | 18°C | 4°C | 10.8°C | 27 mm |
| May | 23°C | 8°C | 15.3°C | 29 mm |
| June | 27°C | 11°C | 19.2°C | 18 mm |
| July | 32°C | 15°C | 23.7°C | 7 mm |
| August | 32°C | 14°C | 22.8°C | 5 mm |
| September | 27°C | 9°C | 18.1°C | 9 mm |
| October | 19°C | 4°C | 11.6°C | 19 mm |
| November | 10°C | −1°C | 4.7°C | 27 mm |
| December | 5°C | −4°C | 0.0°C | 28 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Nampa (9 miles away), gets 10 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00102444; 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 Deer Flat Dam?
Normal highs sit between 65°F and 85°F in May, June, September and October. Of those, September has the fewest days with rain (2).
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 USC00102444.
When is the last frost at Deer Flat Dam?
In Deer Flat Dam, the last spring frost (32°F) comes after April 23 in half of years and after May 9 in one year in ten; the first autumn frost comes before October 18 in half of years and before October 2 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
- April 231 year in 10 after May 9; 9 in 10 after April 5
- First autumn frost, half of years before
- October 181 year in 10 before October 2; 9 in 10 before November 1
NOAA puts the median frost-free season at 178 days, and the season without a hard freeze (28°F) at 207 days.
A hard freeze (28°F) comes after April 5 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Deer Flat Dam in zone 7a in ZIP code 83626, 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 USC00102444; 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 Deer Flat Dam?
In a normal year in Deer Flat Dam, 41 days a year reach 90°F (1 of them 100°F or more), 106 nights fall to 32°F or colder and 72 days bring measurable precipitation.
- Days at 90°F or more
- 41a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 106a normal year
- Days that stay below freezing
- 12high of 32°F or less
- Days with 0.01 inch of precipitation
- 72a normal year
The highest temperature in this station's record (since 1916) is 104°F, on July 3, 1924; the lowest is −27°F, on January 27, 1957.
The wettest calendar year on that record is 1983, with 15.73 in; the snowiest season is 1956–57, with 36.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00102444; records: ACIS (NOAA Regional Climate Centers), station USC00102444. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Deer Flat Dam?
Over a year 82% of the sunlight that would reach the ground under clear skies gets through the clouds at Deer Flat Dam, 4.6 kWh per square metre a day. July is the sunniest month (92%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.7 |
| February | 70% | 2.7 |
| March | 72% | 4.0 |
| April | 77% | 5.5 |
| May | 81% | 6.7 |
| June | 86% | 7.5 |
| July | 92% | 7.7 |
| August | 92% | 6.7 |
| September | 89% | 5.2 |
| October | 82% | 3.5 |
| November | 71% | 2.1 |
| December | 62% | 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 many heating and cooling degree days does Deer Flat Dam record?
A normal year at Deer Flat Dam brings 5,287 heating degree days, 2% fewer than the median U.S. place (5,373), and 771 cooling degree days, 15% 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 2,992 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,018 | 0 |
| February | 774 | 0 |
| March | 586 | 0 |
| April | 408 | 2 |
| May | 200 | 31 |
| June | 59 | 104 |
| July | 5 | 301 |
| August | 8 | 258 |
| September | 87 | 72 |
| October | 382 | 4 |
| November | 738 | 0 |
| December | 1,021 | 0 |
| Year (annual) | 5,287 | 771 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00102444. 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.
How does Deer Flat Dam's climate compare?
Deer Flat Dam is warmer than 78 of the 85 places with their own NOAA record in Idaho, and wetter than 13. Across the 7,247 U.S. stations with normals, its annual mean of 52.5°F is warmer than 52%.
In the Köppen classification computed from these normals, Deer Flat 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 Deer Flat Dam share this climate record?
Marsing 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.
- Marsing, ID1,245 people · 4 mi SW
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 Deer Flat Dam's climate
What is the coldest month at Deer Flat Dam?
December, with a normal high of 40°F and a normal low of 24°F. The warmest is July (90°F by day, 59°F at night).
Does it snow at Deer Flat Dam?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Nampa (9 miles away), records 10 inches of snow in a normal year.
What is the rainiest month at Deer Flat Dam?
January, with 1.22 in of precipitation in a normal year; the driest is August with 0.19 in.
What plant hardiness zone is Deer Flat Dam in?
The USDA's 2023 map puts Deer Flat Dam in zone 7a in ZIP code 83626, the nearest ZIP area.
How late can frost come at Deer Flat Dam?
In half of years the last 32°F night comes after April 23; in one year in ten it comes after May 9. Waiting until May 9 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Nampa, ID9 miles from this station, 52.0°F a year
- Homedale, ID9 miles from this station, 51.8°F a year
- Parma, ID19 miles from this station, 51.5°F a year
- Rockville (5 mi N), OR24 miles from this station, 48.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made