Petersburg, MI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Petersburg, a city in Monroe County, Michigan.
Today
70°F
Showers And Thunderstorms
Rain showers before 11am, then showers and thunderstorms between 11am and 3pm, then a chance of showers and thunderstorms between 3pm and 5pm, then a chance of showers and thunderstorms. Cloudy. High near 70, with temperatures falling to around 66 in the afternoon. East wind 3 to 8 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Petersburg
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 70°F | Showers And Thunderstorms | 3 to 8 mph E | 81% |
| Tonight | 61°F | Patchy Fog | 3 to 7 mph ESE | 84% |
| Sunday | 70°F | Patchy Fog | 6 to 12 mph NNW | 63% |
| Sunday Night | 51°F | Slight Chance Rain Showers then Mostly Cloudy | 12 mph NE | 18% |
| Monday | 63°F | Mostly Cloudy | 14 mph NE | 13% |
| Monday Night | 48°F | Mostly Cloudy | 10 to 14 mph NE | 14% |
| Tuesday | 62°F | Mostly Cloudy then Slight Chance Rain Showers | 15 to 18 mph NE | 16% |
| Tuesday Night | 50°F | Chance Rain Showers | 16 mph ENE | 49% |
| Wednesday | 62°F | Rain Showers Likely | 14 to 17 mph ENE | 58% |
| Wednesday Night | 51°F | Showers And Thunderstorms Likely | 7 to 13 mph ENE | 58% |
| Thursday | 64°F | Slight Chance Rain Showers then Mostly Cloudy | 10 mph NE | 18% |
| Thursday Night | 50°F | Mostly Cloudy | 5 to 9 mph NE | 11% |
| Friday | 68°F | Mostly Sunny | 9 mph NE | 10% |
| Friday Night | 49°F | Partly Cloudy | 3 to 7 mph NE | 7% |
Forecast source: National Weather Service (api.weather.gov) for Petersburg (41.900, -83.714). Updated through the day.
Growing snapshot for Petersburg
Last spring frost
Apr 27
First fall frost
Oct 21
Growing season
176 days
Hardiness zone
6a
More local growing data for Petersburg: nearby ZIP 49270 weather · frost dates · planting calendar · Michigan frost dates
Nearby towns & communities
Carleton
Detroit Beach
Dundee
Estral Beach
Ida
Lambertville
Luna Pier
Maybee
Milan
Monroe
South Monroe
South Rockwood
Stony Point
Temperance
West Monroe
Woodland Beach
Climate data from the nearest NOAA station, Dundee, Mi (5.9 mi from Petersburg). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.