Friday, July 31 night–Sunday night, Aug. 2: Small Craft Advisory for Sheboygan-to-Port Washington (LMZ643)
Sheboygan County, WI — July 31, 2026.
Small Craft Advisory for Sheboygan to Port Washington (LMZ643): begins late Friday night, runs into Sunday night
At 101 PM CDT Friday, July 31, the National Weather Service (NWS) Milwaukee/Sullivan said a Small Craft Advisory is expected to begin late Friday night for the nearshore waters from Sheboygan to Port Washington (LMZ643) and remain in effect into Sunday night.
NWS also noted isolated thunderstorms may develop this afternoon into tonight, a factor for Friday-night plans on or near the water.
What a Small Craft Advisory means (NWS marine definition)
According to NWS marine definitions, it’s an advisory in coastal waters for winds from 20 to 33 knots and/or for seas that are (or are predicted to be) potentially hazardous to small boats.
What Sheboygan County residents should do next
- Check the latest NWS marine updates for LMZ643 before launching or heading back out.
- Be ready to shorten plans or get off the water early if thunderstorms or wind conditions worsen Friday night into Saturday.
- Use a weather-ready routine: the Wisconsin DNR advises keeping a close eye on conditions and bringing a radio, since sudden wind shifts, lightning, and choppy water can signal a storm brewing.
For families planning weekend Lake Michigan time between Sheboygan and Port Washington, this is a practical “conditions can change fast” heads-up—especially with isolated thunderstorms possible into Friday night.
