Harman US

Portland, MI Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Portland, a city in Ionia County, Michigan.

Tonight
52°F
Mostly Cloudy then Chance Rain Showers
A chance of rain showers after 2am. Mostly cloudy. Low around 52, with temperatures rising to around 55 overnight. East northeast wind around 10 mph, with gusts as high as 21 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch possible.

7-day forecast for Portland

WhenTempForecastWindPrecip
Tonight 52°F Mostly Cloudy then Chance Rain Showers 10 mph ENE 47%
Saturday 66°F Showers And Thunderstorms 6 to 10 mph ESE 80%
Saturday Night 55°F Showers And Thunderstorms 6 to 9 mph E 79%
Sunday 67°F Rain Showers Likely 9 to 14 mph NE 58%
Sunday Night 49°F Chance Rain Showers then Mostly Cloudy 10 to 14 mph NE 33%
Monday 63°F Mostly Cloudy 15 mph ENE 11%
Monday Night 45°F Mostly Cloudy 12 to 17 mph NE 11%
Tuesday 62°F Partly Sunny then Slight Chance Rain Showers 16 mph NE 17%
Tuesday Night 47°F Chance Rain Showers 12 to 16 mph NE 32%
Wednesday 63°F Chance Rain Showers 13 mph NE 32%
Wednesday Night 48°F Slight Chance Rain Showers then Mostly Cloudy 6 to 13 mph NE 23%
Thursday 66°F Partly Sunny 7 to 10 mph NE 6%
Thursday Night 49°F Mostly Cloudy 3 to 9 mph NNE 4%
Friday 70°F Mostly Sunny 5 to 9 mph NNE 7%

Forecast source: National Weather Service (api.weather.gov) for Portland (42.870, -84.899). Updated through the day.

Growing snapshot for Portland

Last spring frost
May 3
First fall frost
Oct 12
Growing season
161 days
Hardiness zone
6a

More local growing data for Portland: nearby ZIP 48875 weather · frost dates · planting calendar · Michigan frost dates

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Climate data from the nearest NOAA station, Ionia 2Ssw, Mi (9.4 mi from Portland). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.