Oulu’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 79°, a January night drops to 3°, and about 74 inches of snow falls in a normal winter.
A year in Oulu at a glance
Each month’s typical high and low, and what it brings.
What stands out about Oulu’s climate
Compared with towns across the U.S., with Oulu’s place in Wisconsin beside it.
What a year in Oulu feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 124 frost-free days a year
In half of years the last 32° night comes by May 24 and the first by September 26. Frost and day counts come from NOAA’s station at Brule Rs, WI, 8 miles from the town’s center, at about the same height.
The 2023 USDA map puts Oulu’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −24°. 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 74 inches of snow a winter
Snow, measured at Drummond, WI, falls mostly in January. Precipitation (rain plus melted snow) adds up to 31 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 112 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Oulu
97% 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 Brule Rs, WI.
Living with Oulu’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
124 frost-free days in zone 4b. The last frost comes by May 24 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 26.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 4.8 miles of trails are waiting.
Parks & trails →Cold waves are 47% of the yearly building losses FEMA expects in Oulu from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Oulu and its neighbors
Every town next door is within a degree of Oulu in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Oulu’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 |
|---|---|---|---|---|
| Oulu, WI | 3° | 79° | 31" | 74" |
| Iron Mountain, MI | 5° | 80° | 29" | 61" |
| Beekmantown, NY | 9° | 80° | 35" | 80" |
| St. Joseph, MN | 3° | 81° | 30" | 57" |
| Littleton, NH | 6° | 80° | 40" | 68" |
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 Oulu averaged 1.7° warmer than the 1900s. The biggest change is in January (+3.8°).
A bigger shift than in 69% 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 Oulu compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Oulu’s place among Wisconsin’s.
Oulu weather by month
Highs, lows and precipitation from NOAA’s grid at Oulu’s center; snow, wet days and snow on the ground from Drummond, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 21° | 3° | 1.1" | 15.5" | 9 | −1° – 26° |
| February | 27° | 6° | 1.0" | 12.1" | 6 | 6° – 32° |
| March | 38° | 17° | 1.5" | 12.5" | 8 | 19° – 40° |
| April | 51° | 29° | 2.6" | 6.5" | 10 | 33° – 46° |
| May | 65° | 39° | 3.4" | 0.1" | 10 | 47° – 57° |
| June | 74° | 49° | 4.0" | 0.0" | 11 | 58° – 64° |
| July | 79° | 55° | 4.1" | 0.0" | 11 | 61° – 72° |
| August | 77° | 54° | 3.7" | 0.0" | 10 | 59° – 69° |
| September | 68° | 46° | 3.2" | 0.0" | 10 | 50° – 61° |
| October | 54° | 35° | 3.1" | 1.2" | 10 | 38° – 48° |
| November | 38° | 23° | 1.9" | 12.9" | 8 | 22° – 40° |
| December | 26° | 11° | 1.5" | 13.4" | 9 | 7° – 28° |
| Year | 51° | 30° | 31.0" | 74.2" | 112 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from -1° to 26°. June is the most reliable, staying within 6°.
Where Oulu’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 Oulu’s center.
- Snow: Drummond, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Brule Rs, WI, 8 miles from the town’s center, at about the same height; 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 Oulu’s climate
What is the weather like in Oulu?
A typical July afternoon reaches 79°, a January night drops to 3°, and about 74 inches of snow falls in a normal winter. Colder January nights than all but 118 U.S. towns; cooler July afternoons than 95% of U.S. towns.
How cold does it get in Oulu in winter?
January nights average 3°. About 190 nights a year reach 32° or below and 39 reach 0° or below. In the coldest January of the last 30 years the month averaged −1°.
How much snow does Oulu get?
About 74 inches in a normal winter at Drummond, WI, most of it in January.
How hot does it get in Oulu?
July, with a typical high of 79° and a low of 55°. About 4 days a year reach 90° (Brule Rs, WI).
When is the first and last frost in Oulu?
In half of years the last spring frost (32°) comes by May 24 and the first fall frost by September 26, about 124 frost-free days, at Brule Rs, WI.
What growing zone is Oulu in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −24°.
What is the best time of year to visit Oulu?
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 Oulu getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 69% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Oulu.
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.