Iron Mountain-Kingsford Wastewater Treatment Plant, Michigan climate: Climate normals at a NOAA weather station
Iron Mountain-Kingsford Wastewater Treatment Plant's normal year runs from 4°F January nights to 80°F July afternoons, with 31.5 inches of precipitation and 61 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.8°C, January lows of −15°C, July highs of 27°C, 800 mm of precipitation a year.
- NOAA stationIron Mountain-Kingsford Wastewater Treatment Plant
- Station IDUSC00204090
- Location45.79°N 88.08°W
- Elevation1,071 ft (326 m)
On October 22, the normal high in Iron Mountain-Kingsford Wastewater Treatment Plant is 53°F and the normal low 33°F, and the chance of measurable rain or snow is 36%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Iron Mountain-Kingsford Wastewater Treatment Plant.
- Jan 24° 4°
- Feb 28° 6°
- Mar 39° 17°
- Apr 52° 29°
- May 66° 42°
- Jun 76° 52°
- Jul 80° 57°
- Aug 78° 55°
- Sep 70° 47°
- Oct 56° 35°
- Nov 41° 24°
- 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 at Iron Mountain-Kingsford Wastewater Treatment Plant each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of 4°F. The most precipitation falls in June (3.71 in), the least in February (1.15 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 24°F | 4°F | 14.2°F | 1.36 | 14.7 | 10 | <1 | 31 | 9 h |
| February | 28°F | 6°F | 17.2°F | 1.15 | 11.2 | 7 | <1 | 28 | 10 h 20 min |
| March | 39°F | 17°F | 28.0°F | 1.68 | 8.9 | 8 | <1 | 28 | 11 h 50 min |
| April | 52°F | 29°F | 40.5°F | 2.79 | 7.1 | 10 | <1 | 20 | 13 h 30 min |
| May | 66°F | 42°F | 54.1°F | 3.48 | 0.2 | 12 | <1 | 5 | 14 h 50 min |
| June | 76°F | 52°F | 64.0°F | 3.71 | 0.0 | 12 | 1 | <1 | 15 h 40 min |
| July | 80°F | 57°F | 68.5°F | 3.41 | 0.0 | 12 | 3 | <1 | 15 h 20 min |
| August | 78°F | 55°F | 66.7°F | 3.38 | 0.0 | 11 | 1 | <1 | 14 h 10 min |
| September | 70°F | 47°F | 58.6°F | 3.60 | 0.0 | 11 | <1 | 1 | 12 h 40 min |
| October | 56°F | 35°F | 45.3°F | 3.27 | 0.4 | 12 | <1 | 13 | 11 h |
| November | 41°F | 24°F | 32.5°F | 1.90 | 5.5 | 9 | <1 | 25 | 9 h 30 min |
| December | 29°F | 13°F | 20.9°F | 1.76 | 13.0 | 10 | <1 | 30 | 8 h 40 min |
| Year (annual) | 53°F | 32°F | 42.5°F | 31.49 | 61.0 | 122 | 6 | 182 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −4°C | −15°C | −9.9°C | 35 mm | 37 cm |
| February | −2°C | −14°C | −8.2°C | 29 mm | 28 cm |
| March | 4°C | −8°C | −2.2°C | 43 mm | 23 cm |
| April | 11°C | −2°C | 4.7°C | 71 mm | 18 cm |
| May | 19°C | 5°C | 12.3°C | 88 mm | 1 cm |
| June | 24°C | 11°C | 17.8°C | 94 mm | 0 cm |
| July | 27°C | 14°C | 20.3°C | 87 mm | 0 cm |
| August | 26°C | 13°C | 19.3°C | 86 mm | 0 cm |
| September | 21°C | 8°C | 14.8°C | 91 mm | 0 cm |
| October | 13°C | 2°C | 7.4°C | 83 mm | 1 cm |
| November | 5°C | −4°C | 0.3°C | 48 mm | 14 cm |
| December | −2°C | −11°C | −6.2°C | 45 mm | 33 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00204090; 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 Iron Mountain-Kingsford Wastewater Treatment Plant?
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 (11).
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 USC00204090.
When is the last frost at Iron Mountain-Kingsford Wastewater Treatment Plant?
In Iron Mountain-Kingsford Wastewater Treatment Plant, the last spring frost (32°F) comes after May 17 in half of years and after May 31 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 17 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 May 31; 9 in 10 after May 2
- First autumn frost, half of years before
- October 11 year in 10 before September 17; 9 in 10 before October 13
NOAA puts the median frost-free season at 135 days, and the season without a hard freeze (28°F) at 157 days.
A hard freeze (28°F) comes after May 4 in half of springs and before October 11 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Iron Mountain-Kingsford Wastewater Treatment Plant in zone 4b in ZIP code 49802, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 4b: the coldest night of a typical year reaches −21°F (30 complete years).
Frost dates for every NOAA station in Michigan · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00204090; 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 at Iron Mountain-Kingsford Wastewater Treatment Plant?
In a normal year in Iron Mountain-Kingsford Wastewater Treatment Plant, 6 days a year reach 90°F, 182 nights fall to 32°F or colder and 122 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 182a normal year
- Days that stay below freezing
- 79high of 32°F or less
- Days with 0.01 inch of precipitation
- 122a normal year
- Days with 1 inch of snow or more
- 21a normal year
The highest temperature in this station's record (since 1899) is 104°F, on July 29, 1917; the lowest is −39°F, on February 1, 1938.
The wettest calendar year on that record is 2017, with 39.31 in; the snowiest season is 1938–39, with 128.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00204090; records: ACIS (NOAA Regional Climate Centers), station USC00204090. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Iron Mountain-Kingsford Wastewater Treatment Plant?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds at Iron Mountain-Kingsford Wastewater Treatment Plant, 3.7 kWh per square metre a day. July is the sunniest month (78%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 1.6 |
| February | 73% | 2.6 |
| March | 73% | 3.8 |
| April | 68% | 4.6 |
| May | 69% | 5.4 |
| June | 72% | 6.0 |
| July | 78% | 6.1 |
| August | 76% | 5.1 |
| September | 73% | 3.9 |
| October | 65% | 2.5 |
| November | 61% | 1.5 |
| 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 many heating and cooling degree days does Iron Mountain-Kingsford Wastewater Treatment Plant record?
A normal year at Iron Mountain-Kingsford Wastewater Treatment Plant brings 8,522 heating degree days, 59% more than the median U.S. place (5,373), and 372 cooling degree days, 59% 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 2,062 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,575 | 0 |
| February | 1,338 | 0 |
| March | 1,146 | 0 |
| April | 737 | 0 |
| May | 357 | 18 |
| June | 103 | 73 |
| July | 36 | 144 |
| August | 52 | 105 |
| September | 225 | 31 |
| October | 612 | 1 |
| November | 975 | 0 |
| December | 1,367 | 0 |
| Year (annual) | 8,522 | 372 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00204090. 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.
Have recent years at Iron Mountain-Kingsford Wastewater Treatment Plant been warmer than normal?
2025 averaged 43.7°F, 1.2°F above the 1991-2020 normal of 42.5°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 44.8°F | +2.3°F | 26.40 | 58.3 |
| 2022 | 42.0°F | −0.5°F | 32.19 | 42.8 |
| 2023 | 44.8°F | +2.3°F | 28.65 | 71.9 |
| 2024 | 46.3°F | +3.8°F | 30.97 | 38.0 |
| 2025 | 43.7°F | +1.2°F | 29.64 | 59.3 |
Over 102 complete years from 1902 to 2025, the station's annual mean temperature rose at a fitted 2.8°F per century (+0.15°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00204090; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Iron Mountain-Kingsford Wastewater Treatment Plant's climate compare?
Iron Mountain-Kingsford Wastewater Treatment Plant is warmer than 18 of the 140 places with their own NOAA record in Michigan, and wetter than 19. Across the 7,247 U.S. stations with normals, its annual mean of 42.5°F is warmer than 11%.
In the Köppen classification computed from these normals, Iron Mountain-Kingsford Wastewater Treatment Plant 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 Iron Mountain-Kingsford Wastewater Treatment Plant share this climate record?
5 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.
- Norway, MI2,840 people · 8 mi E
- Niagara, WI1,579 people · 4 mi E
- Quinnesec, MI1,150 people · 4 mi E
- Pembine, WI250 people · 11 mi SE
- Dunbar, WI105 people · 11 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 Iron Mountain-Kingsford Wastewater Treatment Plant's climate
What is the coldest month at Iron Mountain-Kingsford Wastewater Treatment Plant?
January, with a normal high of 24°F and a normal low of 4°F. The warmest is July (80°F by day, 57°F at night).
Does it snow at Iron Mountain-Kingsford Wastewater Treatment Plant?
Yes: 61 inches in a normal year, falling on 36 days with 0.1 inch or more, the most in January (14.7 inches).
What is the rainiest month at Iron Mountain-Kingsford Wastewater Treatment Plant?
June, with 3.71 in of precipitation in a normal year; the driest is February with 1.15 in.
What plant hardiness zone is Iron Mountain-Kingsford Wastewater Treatment Plant in?
The USDA's 2023 map puts Iron Mountain-Kingsford Wastewater Treatment Plant in zone 4b in ZIP code 49802, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −21°F (30 years, 1991-2020): zone 4b.
How late can frost come at Iron Mountain-Kingsford Wastewater Treatment Plant?
In half of years the last 32°F night comes after May 17; in one year in ten it comes after May 31. Waiting until May 31 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Michigan climateThe statewide normals and every place in the state
- Iron Mountain, MI2 miles from this station, 41.8°F a year
- Florence, WI13 miles from this station, 40.4°F a year
- Goodman, WI17 miles from this station, 41.3°F a year
- Crivitz, WI30 miles from this station, 41.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made