Merrimac, WI
Full City Profile · Wisconsin · Sauk County County
4.5
/5.0
A+
Excellent
575
Population
701/sq mi density
$102,344
Median Income
$47,043 per capita
$274,200
Home Value
$497,725 Zillow
$1,050
Median Rent
9.0% income on rent
47°F
Avg Temperature
A+
Overall
4.5 / 5.0
Strong
A+
Economy
5.0 / 5.0
$102,344 median income, 1.3% unemployment
A+
Affordability
5.0 / 5.0
$274,200 home value, $1,050/mo rent
B+
Education
3.6 / 5.0
32.7% bachelor's degree or higher
Merrimac experiences four distinct seasons with an average annual temperature of 47°F (8°C). Winters average 19°F in January while summers reach 72°F in July. Annual precipitation totals 39.2 inches. The area receives 42.7 inches of snow annually. Air quality is rated Good with a median AQI of 37.
Temperature
19°F Jan (-8°C)
72°F Jul (22°C)
| Annual Average | 47.1°F |
| 13% below US avg | |
| January Average | 19°F (-8°C) |
| July Average | 72°F (22°C) |
Geography
| Elevation | 811 ft (247 m) |
| Area | 1.5 sq mi (3.9 km²) |
| Population Density | 701/sq mi |
| Coordinates | 43.3756°N, 89.6269°W |
| Timezone | America/Chicago |
| County | Sauk County County |
| Nearest Airport | Dane County Regional/Truax Field (MSN) 22 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 37.0 |
| Rating | Good |
| Good Days % | 85.2% |
| Unhealthy Days | 0 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0488 ppm |
| PM2.5 (Fine Particles) | 9.1 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 72.1 / 100 |
| Social Vulnerability | 21.9 / 100 |
| Community Resilience | 82.6 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Very Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Low |
| Drought | Relatively Low |
| Cold Wave | Relatively Moderate |
| Landslide | Relatively Moderate |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 19°F (-8°C) | 1.5 in | Coldest, Driest |
| February | 22°F (-5°C) | 1.5 in | |
| March | 34°F (1°C) | 2.2 in | |
| April | 46°F (8°C) | 4.0 in | |
| May | 59°F (15°C) | 4.6 in | |
| June | 69°F (20°C) | 5.4 in | Wettest |
| July | 72°F (22°C) | 4.9 in | Warmest |
| August | 70°F (21°C) | 4.4 in | |
| September | 62°F (17°C) | 3.8 in | |
| October | 50°F (10°C) | 3.0 in | |
| November | 37°F (3°C) | 2.3 in | |
| December | 25°F (-4°C) | 1.7 in |
Merrimac has a seasonal temperature swing of 54°F / from 19°F in January to 72°F in July. Total annual precipitation is 39.2 inches, with June being the wettest month (5.4") and January the driest (1.5").