Photo: Tim Kiser (w:User:Malepheasant) · CC BY-SA 2.5Ontonagon gets about 178 inches of snow a winter, more than all but 34 U.S. towns
The warmest part of a July day comes in at 76° on average. Rain follows the seasons: July brings about 2.6 times as much as February. By July afternoons alone, it runs cooler than 98% of U.S. towns. Seedlings are safe outdoors from about May 27, with the first autumn frost due around October 1.
A year in Ontonagon at a glance
Each month’s typical high and low, and what it brings.
What stands out about Ontonagon’s climate
Compared with towns across the U.S., with Ontonagon’s place in Michigan beside it.
What a year in Ontonagon feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 127 frost-free days a year
In half of years the last 32° night comes by May 27 and the first by October 1. Frost and day counts come from NOAA’s station at Ontonagon 6 Se, MI, 5 miles from the town’s center, 160 ft higher.
The 2023 USDA map puts Ontonagon’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −16°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 178 inches of snow a winter
Snow, measured at Ontonagon 6 Se, MI, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 32 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 142 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Ontonagon
96% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Ontonagon 6 Se, MI.
Living with Ontonagon’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
127 frost-free days in zone 5a. The last frost comes by May 27 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 1.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 4.4 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Ontonagon from natural hazards, river flooding is the largest share (52%); heat waves, cold waves, winter storms and ice storms together are 39%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Ontonagon and its neighbors
Ontonagon Township the hottest July afternoons (77°, 1° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Ontonagon’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Ontonagon, MI | 9° | 76° | 32" | 178" |
| Woodland Park, CO | 11° | 77° | 22" | 134" |
| Morristown, VT | 7° | 78° | 43" | 139" |
| Summit Park, UT | 19° | 79° | 30" | 153" |
| Wilna, NY | 8° | 79° | 42" | 127" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Ontonagon averaged 1.6° warmer than the 1900s. The biggest change is in December (+3.2°).
A bigger shift than in 68% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Ontonagon compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Ontonagon’s place among Michigan’s.
Ontonagon weather by month
Highs, lows and precipitation from NOAA’s grid at Ontonagon’s center; snow, wet days and snow on the ground from Ontonagon 6 Se, MI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 24° | 9° | 2.2" | 53.1" | 18 | 4° – 27° |
| February | 27° | 9° | 1.4" | 27.0" | 12 | 5° – 32° |
| March | 37° | 17° | 1.6" | 17.6" | 9 | 16° – 43° |
| April | 48° | 29° | 2.6" | 6.9" | 9 | 29° – 46° |
| May | 61° | 39° | 3.0" | 1.0" | 10 | 43° – 57° |
| June | 71° | 49° | 3.1" | 0.0" | 11 | 55° – 65° |
| July | 76° | 55° | 3.6" | 0.0" | 11 | 58° – 69° |
| August | 75° | 55° | 3.1" | 0.0" | 9 | 59° – 69° |
| September | 67° | 48° | 3.4" | 0.1" | 11 | 51° – 63° |
| October | 54° | 37° | 3.5" | 2.5" | 14 | 40° – 51° |
| November | 40° | 27° | 2.5" | 21.4" | 13 | 25° – 43° |
| December | 29° | 16° | 2.1" | 48.1" | 16 | 12° – 32° |
| Year | 51° | 32° | 32.0" | 177.7" | 142 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 5° to 32°. June is the most reliable, staying within 10°.
Where Ontonagon’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Ontonagon’s center.
- Snow: Ontonagon 6 Se, MI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ontonagon 6 Se, MI, 5 miles from the town’s center, 160 ft higher; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Ontonagon’s climate
What is the weather like in Ontonagon?
A typical July afternoon reaches 76°, a January night drops to 9°, and about 178 inches of snow falls in a normal winter. Colder January nights than 95% of U.S. towns; cooler July afternoons than 98% of U.S. towns.
How cold does it get in Ontonagon in winter?
January nights average 9°. About 175 nights a year reach 32° or below and 25 reach 0° or below. In the coldest January of the last 30 years the month averaged 4°.
How much snow does Ontonagon get?
About 178 inches in a normal winter at Ontonagon 6 Se, MI, most of it in January and December.
How hot does it get in Ontonagon?
July, with a typical high of 76° and a low of 55°. About 6 days a year reach 90° (Ontonagon 6 Se, MI).
When is the first and last frost in Ontonagon?
In half of years the last spring frost (32°) comes by May 27 and the first fall frost by October 1, about 127 frost-free days, at Ontonagon 6 Se, MI.
What growing zone is Ontonagon in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −16°.
What is the best time of year to visit Ontonagon?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Ontonagon getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 68% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Ontonagon.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.