Alpena, Michigan climate: Normal weather by month, frost dates and records
Alpena's normal year runs from 12°F January nights to 81°F July afternoons, with 29.7 inches of precipitation and 78 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.8°C, January lows of −11°C, July highs of 27°C, 754 mm of precipitation a year.
- NOAA stationAlpena County Regional Airport
- Station IDUSW00094849
- Location45.07°N 83.56°W
- Elevation684 ft (209 m)
- Population10,116
On October 23, the normal high in Alpena is 54°F and the normal low 35°F, and the chance of measurable rain or snow is 45%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Alpena.
- Jan 28° 12°
- Feb 30° 11°
- Mar 39° 19°
- Apr 52° 30°
- May 66° 41°
- Jun 76° 50°
- Jul 81° 56°
- Aug 79° 55°
- Sep 71° 47°
- Oct 58° 37°
- Nov 45° 29°
- Dec 34° 20°
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 Alpena each month?
July is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of 12°F. The most precipitation falls in July (3.20 in), the least in February (1.52 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 28°F | 12°F | 20.0°F | 1.81 | 19.3 | 16 | <1 | 30 | 9 h 10 min |
| February | 30°F | 11°F | 20.7°F | 1.52 | 17.0 | 12 | <1 | 27 | 10 h 20 min |
| March | 39°F | 19°F | 29.3°F | 1.81 | 10.6 | 11 | <1 | 28 | 11 h 50 min |
| April | 52°F | 30°F | 41.2°F | 2.93 | 6.6 | 12 | <1 | 19 | 13 h 30 min |
| May | 66°F | 41°F | 53.4°F | 2.78 | 0.2 | 12 | <1 | 5 | 14 h 50 min |
| June | 76°F | 50°F | 63.2°F | 2.74 | 0.0 | 10 | 2 | <1 | 15 h 40 min |
| July | 81°F | 56°F | 68.2°F | 3.20 | 0.0 | 11 | 3 | <1 | 15 h 20 min |
| August | 79°F | 55°F | 66.6°F | 3.09 | 0.0 | 10 | 2 | <1 | 14 h 10 min |
| September | 71°F | 47°F | 59.0°F | 2.84 | 0.0 | 11 | 1 | 1 | 12 h 40 min |
| October | 58°F | 37°F | 47.4°F | 3.01 | 0.4 | 14 | <1 | 10 | 11 h |
| November | 45°F | 29°F | 36.6°F | 2.07 | 6.6 | 14 | <1 | 21 | 9 h 40 min |
| December | 34°F | 20°F | 26.6°F | 1.87 | 16.9 | 14 | <1 | 28 | 8 h 50 min |
| Year (annual) | 55°F | 34°F | 44.3°F | 29.67 | 77.6 | 145 | 7 | 169 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −11°C | −6.7°C | 46 mm | 49 cm |
| February | −1°C | −12°C | −6.3°C | 39 mm | 43 cm |
| March | 4°C | −7°C | −1.5°C | 46 mm | 27 cm |
| April | 11°C | −1°C | 5.1°C | 74 mm | 17 cm |
| May | 19°C | 5°C | 11.9°C | 71 mm | 1 cm |
| June | 24°C | 10°C | 17.3°C | 70 mm | 0 cm |
| July | 27°C | 13°C | 20.1°C | 81 mm | 0 cm |
| August | 26°C | 13°C | 19.2°C | 78 mm | 0 cm |
| September | 22°C | 8°C | 15.0°C | 72 mm | 0 cm |
| October | 14°C | 3°C | 8.6°C | 76 mm | 1 cm |
| November | 7°C | −2°C | 2.6°C | 53 mm | 17 cm |
| December | 1°C | −7°C | −3.0°C | 47 mm | 43 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094849; 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 Alpena?
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 (10).
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 USW00094849.
When is the last frost in Alpena?
In Alpena, 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 18 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 1
- First autumn frost, half of years before
- October 11 year in 10 before September 18; 9 in 10 before October 16
NOAA puts the median frost-free season at 136 days, and the season without a hard freeze (28°F) at 162 days.
A hard freeze (28°F) comes after May 4 in half of springs and before October 15 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Alpena in zone 5b in ZIP code 49707, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Alpena's NOAA station is in zone 5b: the coldest night of a typical year reaches −15°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 USW00094849; 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 Alpena?
In a normal year in Alpena, 7 days a year reach 90°F, 169 nights fall to 32°F or colder and 145 days bring measurable precipitation.
- Days at 90°F or more
- 7a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 169a normal year
- Days that stay below freezing
- 68high of 32°F or less
- Days with 0.01 inch of precipitation
- 145a normal year
- Days with 1 inch of snow or more
- 26a normal year
The highest temperature in Alpena's official record (kept by the National Weather Service since 1916) is 106°F, on July 13, 1936; the lowest is −37°F, on February 17, 1979.
The wettest calendar year on that record is 2017, with 40.15 in; the snowiest season is 1970–71, with 166.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00094849; records: ACIS (NOAA Regional Climate Centers), NWS threaded record APNthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Alpena, and how clear are its skies?
The summer (June-August) dew point averages 57°F. The muggiest month is July, with an average dew point of 58°F; the driest air comes in January (14°F). March is the windiest month (8.4 mph on average), and July has the most clear or nearly clear hours (62%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 14°F | 76% | 66% | 7.8 mph | 27% | 58% |
| February | 16°F | 74% | 60% | 8.0 mph | 37% | 50% |
| March | 25°F | 67% | 50% | 8.4 mph | 46% | 40% |
| April | 34°F | 62% | 44% | 8.1 mph | 55% | 30% |
| May | 47°F | 68% | 49% | 6.9 mph | 60% | 24% |
| June | 56°F | 70% | 51% | 6.3 mph | 61% | 19% |
| July | 58°F | 73% | 53% | 5.9 mph | 62% | 15% |
| August | 56°F | 76% | 56% | 6.0 mph | 62% | 19% |
| September | 46°F | 77% | 57% | 6.9 mph | 50% | 31% |
| October | 35°F | 76% | 61% | 7.6 mph | 36% | 50% |
| November | 26°F | 78% | 69% | 8.0 mph | 20% | 68% |
| December | 18°F | 79% | 70% | 8.0 mph | 19% | 69% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00094849. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Alpena?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Alpena, 3.6 kWh per square metre a day. July is the sunniest month (78%) and December the cloudiest (47%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 51% | 1.2 |
| February | 60% | 2.1 |
| March | 70% | 3.6 |
| April | 69% | 4.6 |
| May | 71% | 5.5 |
| June | 74% | 6.0 |
| July | 78% | 6.0 |
| August | 77% | 5.1 |
| September | 75% | 4.0 |
| October | 63% | 2.4 |
| November | 54% | 1.3 |
| December | 47% | 0.9 |
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 Alpena need?
A normal year in Alpena brings 7,844 heating degree days, 46% more than the median U.S. place (5,373), and 353 cooling degree days, 61% 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 2,033 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,395 | 0 |
| February | 1,240 | 0 |
| March | 1,108 | 0 |
| April | 715 | 1 |
| May | 377 | 15 |
| June | 120 | 65 |
| July | 34 | 133 |
| August | 52 | 103 |
| September | 213 | 32 |
| October | 549 | 3 |
| November | 852 | 0 |
| December | 1,190 | 0 |
| Year (annual) | 7,844 | 353 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094849. 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 Alpena been warmer than normal lately?
2025 averaged 44.9°F, 0.6°F above the 1991-2020 normal of 44.3°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 46.9°F | +2.6°F | 26.88 | 55.0 |
| 2022 | 44.5°F | +0.2°F | 30.52 | 63.3 |
| 2023 | 46.6°F | +2.3°F | 30.02 | 58.4 |
| 2024 | 48.4°F | +4.1°F | 33.08 | 58.4 |
| 2025 | 44.9°F | +0.6°F | 27.61 | 79.0 |
Over 97 complete years from 1918 to 2025, the station's annual mean temperature rose at a fitted 2.8°F per century (+0.16°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00094849; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Alpena's climate compare?
Alpena is warmer than 36 of the other 139 places with their own NOAA record in Michigan, and wetter than 8. Across the 7,247 U.S. stations with normals, its annual mean of 44.3°F is warmer than 17%.
In the Köppen classification computed from these normals, Alpena 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 Alpena share this climate record?
Ossineke 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.
- Ossineke, MI888 people · 13 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Alpena's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Alpena. This page uses Alpena County Regional Airport; the others differ by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Alpena (10 mi NW) USC00200166 | 6 mi N | 740 ft | 43.5°F | 11°F | 79°F | – | – | May 13 |
| Alpena Wastewater Treatment Plant USW00014814 | 7 mi E | 590 ft | 44.2°F | 13°F | 77°F | 31.9 | 59 | May 5 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Alpena's climate
What is the coldest month in Alpena?
January, with a normal high of 28°F and a normal low of 12°F. The warmest is July (81°F by day, 56°F at night).
Does it snow in Alpena?
Yes: 78 inches in a normal year, falling on 56 days with 0.1 inch or more, the most in January (19.3 inches).
What is the rainiest month in Alpena?
July, with 3.20 in of precipitation in a normal year; the driest is February with 1.52 in.
What plant hardiness zone is Alpena in?
The USDA's 2023 map puts Alpena in zone 5b in ZIP code 49707, the nearest ZIP area. By the same method at Alpena's NOAA station, the coldest night of a typical year reaches −15°F (30 years, 1991-2020): zone 5b.
How late can frost come in Alpena?
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
- Alpena in OctoberThis month day by day, its records and recent years
- Michigan climateThe statewide normals and every place in the state
- Rogers City, MI27 miles from this station, 44.8°F a year
- Atlanta, MI29 miles from this station, 43.4°F a year
- Harrisville, MI30 miles from this station, 42.8°F a year
- Glennie (2 mi SE), MI38 miles from this station, 42.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made