Sign In Register

Weather & Climate in Delafield, WI

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

Delafield experiences four distinct seasons with an average annual temperature of 47°F (8°C). Winters average 20°F in January while summers reach 71°F in July. The area gets 260 sunny days per year, above the national average. Annual precipitation totals 36.0 inches. The area receives 36.9 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 38. The city sits at an elevation of 904 feet.

Temperature

20°F Jan (-7°C) 71°F Jul (22°C)
Annual Average46.6°F
14% below US avg
January Average20°F (-7°C)
July Average71°F (22°C)
Sunny Days260 days/yr

Geography

Elevation904 ft (276 m)
Area11.0 sq mi (28.6 km²)
Population Density764/sq mi
Coordinates43.0674°N, 88.3888°W
TimezoneAmerica/Chicago
CountyWaukesha County County
Nearest AirportGeneral Mitchell International (MKE)
26 miles away

Precipitation & Snow

Annual Rainfall 36.0"
5% below US avg
Snowfall 36.9"
Wettest Month (Jul) 4.02"
Driest Month (Feb) 1.10"

Air Quality

AQI Median38.0
RatingGood

Natural Hazard Risk

Overall RiskRelatively Moderate
Risk Score88.9 / 100
Social Vulnerability10.6 / 100
Community Resilience97.4 / 100

Hazard Breakdown

Tornado Relatively High
Hurricane Very Low
Earthquake Very Low
Wildfire Very Low
Flood Relatively Moderate
Hail Relatively High
Strong Wind Relatively Moderate
Heat Wave Relatively Moderate
Winter Weather Relatively High
Lightning Relatively Moderate
Ice Storm Relatively Moderate
Drought Relatively Low
Cold Wave Relatively High
Landslide Relatively Low
Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

4 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.8.

Feb 10, 2010 2 km NW of Lily Lake, Illinois M3.8 123 km 10 km
Nov 4, 2013 1 km SSW of Lyons, Illinois M3.2 148 km 1 km
Mar 25, 2015 3 km WNW of Lake in the Hills, Illinois M2.9 98 km 6 km
Jun 10, 2013 4 km NNE of Virgil, Illinois M2.6 120 km 5 km
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.

Tornado History

476 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 22 fatalities, 660 injuries.

Date Rating Distance Path Fatalities
Jul 18, 1996 EF5 73 km 13.3 mi 0
Apr 27, 1984 EF4 10 km 6.5 mi 1
Apr 4, 1981 EF4 43 km 1.8 mi 3
Apr 21, 1974 EF4 84 km 26.0 mi 0
Sep 28, 1972 EF4 97 km 5.2 mi 0
Apr 11, 1965 EF4 94 km 9.1 mi 6
Aug 22, 1964 EF4 52 km 2.2 mi 0
Sep 26, 1951 EF4 83 km 9.0 mi 1
Jun 16, 2014 EF3 95 km 1.0 mi 0
Jan 7, 2008 EF3 58 km 10.8 mi 0
Jan 7, 2008 EF3 84 km 13.2 mi 0
Aug 18, 2005 EF3 86 km 18.6 mi 1
Jun 23, 2004 EF3 81 km 7.6 mi 1
Jun 23, 2004 EF3 89 km 33.3 mi 0
Jun 17, 1992 EF3 95 km 16.0 mi 0
Jun 8, 1984 EF3 80 km 29.0 mi 0
Jun 5, 1980 EF3 32 km 10.7 mi 0
Apr 7, 1980 EF3 66 km 1.2 mi 0
Jun 5, 1977 EF3 88 km 69.5 mi 0
Jun 4, 1975 EF3 71 km 2.3 mi 0
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).

Wildfire History

8 wildfires (100+ acres) recorded within 100 km. Largest: UNNAMED (1,524 acres, 2006).

Year Name Acres Burned Distance
2006 UNNAMED 1,524 54 km
2010 RX BURN 1,236 54 km
1994 SOMMERS 938 60 km
1988 PEACHY RD 812 57 km
2024 IBSP SOUTH F1 RX 690 87 km
2006 UNNAMED 612 62 km
2007 TOWER RD 2 592 57 km
2024 RX-HWY Y - SOUTH 553 31 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month Avg Temperature Precipitation Summary
January 20°F (-7°C) 1.3 in Coldest
February 22°F (-5°C) 1.1 in Driest
March 33°F (1°C) 2.2 in
April 45°F (7°C) 3.1 in
May 57°F (14°C) 3.0 in
June 66°F (19°C) 3.7 in
July 71°F (22°C) 4.0 in Warmest, Wettest
August 69°F (21°C) 3.9 in
September 61°F (16°C) 3.9 in
October 50°F (10°C) 2.6 in
November 36°F (2°C) 2.4 in
December 23°F (-5°C) 1.8 in

Delafield has a seasonal temperature swing of 51°F / from 20°F in January to 71°F in July. Total annual precipitation is 32.9 inches, with July being the wettest month (4.0") and February the driest (1.1").

View full profile of Delafield, WI →