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
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| 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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Sherrard
Viola
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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.