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New Boston, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for New Boston, a city in Mercer County, Illinois.

Tonight
69°F
Mostly Cloudy then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 2am. Mostly cloudy. Low around 69, with temperatures rising to around 71 overnight. Southeast wind 5 to 10 mph. Chance of precipitation is 50%.

7-day forecast for New Boston

WhenTempForecastWindPrecip
Tonight 69°F Mostly Cloudy then Chance Showers And Thunderstorms 5 to 10 mph SE 46%
Saturday 85°F Chance Showers And Thunderstorms then Showers And Thunderstorms Likely 5 mph S 55%
Saturday Night 66°F Chance Showers And Thunderstorms then Showers And Thunderstorms 5 mph N 78%
Sunday 74°F Showers And Thunderstorms 5 to 10 mph NE 77%
Sunday Night 58°F Showers And Thunderstorms Likely 10 to 15 mph NE 72%
Monday 66°F Rain Showers Likely 10 to 15 mph NE 63%
Monday Night 54°F Rain Showers Likely 10 mph NE 57%
Tuesday 63°F Chance Rain Showers 10 mph NE 39%
Tuesday Night 49°F Partly Cloudy 5 to 10 mph NE 6%
Wednesday 68°F Mostly Sunny 5 mph NE 1%
Wednesday Night 53°F Partly Cloudy 0 to 5 mph NE 1%
Thursday 71°F Mostly Sunny 0 to 5 mph NE 6%
Thursday Night 55°F Partly Cloudy 0 to 5 mph NE 6%
Friday 72°F Mostly Sunny 0 to 5 mph NE 6%

Forecast source: National Weather Service (api.weather.gov) for New Boston (41.170, -91.000). Updated through the day.

Growing snapshot for New Boston

Last spring frost
Apr 14
First fall frost
Oct 24
Growing season
190 days
Hardiness zone
5b

More local growing data for New Boston: nearby ZIP 61272 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, New Boston Dam 17, Il (4.7 mi from New Boston). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.