Washtenaw County, Michigan — Weather Alerts & Warnings

No active National Weather Service alerts for Washtenaw County right now. This page is the live destination for Washtenaw County (county seat: Ann Arbor) — bookmark it to check active watches, warnings, and advisories from NWS Detroit/Pontiac, plus regional context, common weather hazards, and the most recent alerts.

Active alerts (0)

✓ No active NWS alerts for Washtenaw County. Conditions are clear from the National Weather Service.

About Washtenaw County

County seat
Ann Arbor
Population (2020)
372,258
Region
Southeast Lower Peninsula (Metro Detroit)
NWS Office

Southeast Michigan — the Metro Detroit region — combines the highest population density in the state with significant severe-weather exposure. Wayne, Oakland, Macomb, Washtenaw, Livingston, and surrounding counties face frequent severe thunderstorms, occasional tornadoes (most notably in Washtenaw and Lenawee), winter storms that can paralyze freeways, and growing concern about urban flash flooding as drainage infrastructure ages. Lakeshore flooding affects Wayne, Macomb, Monroe, and St. Clair counties along Lakes Erie, St. Clair, and Huron.

Washtenaw County is served by NWS Detroit/Pontiac, headquartered in White Lake, MI, which issues all official severe-weather watches, warnings, and advisories for the county under the SAME geographic code MIC161. Alerts shown above come directly from the National Weather Service public-alerts feed and update within seconds of issuance.

Drinking-water quality in Washtenaw County

The U.S. EPA's Safe Drinking Water Information System lists 264 public water systems in Washtenaw County with open health-based violations or recent enforcement activity. These are typically municipal water utilities, mobile-home parks, schools, and private community systems — not bottled water or private household wells. Residents on these systems should have received a Consumer Confidence Report (CCR) by mail; the systems below are listed in order of open violations on file.

Public water system
Open viol.
Actions
Cities served
St. Louis Center MI0006325
23
20
Chelsea
17
20
14
15
14
12
Whitmore Lake
Tippin's Market MI2052481
12
9
12
7
Whitmore Lake
Whitmore Lanes MI2043081
11
8
10
2
8
8

Source: EPA ECHO / Safe Drinking Water Information System. State enforcement context: Michigan EGLE Drinking Water program. A "violation" on this list does not always mean unsafe water today — it includes monitoring and reporting failures alongside acute health-based exceedances. Click any system name for the full ECHO compliance history. Updated May 10, 5:35 AM.

Common weather hazards in Washtenaw County

Based on Washtenaw County's southeast lower peninsula (metro detroit) geography, residents and visitors should be prepared for these recurring weather threats:

severe thunderstormstornadoeswinter stormsflooding

When a Tornado Warning is issued

A Tornado Warning means a tornado has been sighted or indicated by radar in Washtenaw County or an adjacent area — take shelter immediately. Move to the lowest floor of a sturdy building, away from windows, and into an interior room (basement, bathroom, or closet). Mobile homes and vehicles are not safe; if you're in either, leave for a sturdy structure if you can do so safely. Tornado Warnings are typically issued for 30–60 minutes; stay sheltered until the warning expires or NWS Detroit/Pontiac confirms the threat has passed. Washtenaw County residents should monitor a NOAA Weather Radio (programmed for SAME code MIC161), local TV, or this page.

When a Flood Warning is issued

A Flood Warning means flooding is occurring or imminent in Washtenaw County. Do not drive through flooded roads — most flood-related deaths in Michigan occur in vehicles attempting to cross water. If you live in a low-lying area near Ann Arbor or along major waterways in the county, monitor official water-level reports from the U.S. Geological Survey and prepare to move to higher ground. Flash Flood Warnings carry the same urgency on a shorter time horizon — typically less than an hour to act.

When a Winter Storm Warning is issued

Winter Storm Warnings in Washtenaw County indicate hazardous winter weather (heavy snow, freezing rain, sleet, or blizzard conditions) is occurring or imminent. Avoid travel; if you must drive, carry an emergency kit (blankets, food, water, flashlight, charged phone). Heating-source safety is critical: never run generators or grills indoors, and check carbon-monoxide detectors before relying on alternative heat sources.

Nearby Michigan counties

Weather rarely respects county lines — check active alerts in Washtenaw County's neighbors:

Genesee CountyJackson CountyLapeer CountyLenawee CountyLivingston CountyMacomb CountyMonroe CountyOakland County

Get notified about Washtenaw County alerts

Subscribe to push or email notifications for new National Weather Service watches and warnings issued for Washtenaw County. We'll alert you within seconds of NWS Detroit/Pontiac issuing any severe weather warning for SAME code MIC161.