New Boston, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for New Boston, a city in Mercer County, Illinois.
This Afternoon
69°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely. Mostly cloudy, with a high near 69. South wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
7-day forecast for New Boston
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Showers And Thunderstorms Likely | 15 mph S | 63% |
| Tonight | 51°F | Showers And Thunderstorms Likely | 10 to 15 mph S | 62% |
| Wednesday | 55°F | Slight Chance Rain Showers | 15 mph SW | 20% |
| Wednesday Night | 45°F | Mostly Cloudy | 10 to 15 mph SW | 9% |
| Thursday | 55°F | Chance Rain Showers | 5 to 10 mph W | 28% |
| Thursday Night | 42°F | Chance Rain Showers then Mostly Cloudy | 5 to 10 mph NW | 32% |
| Friday | 52°F | Partly Sunny | 5 to 10 mph N | 10% |
| Friday Night | 35°F | Partly Cloudy | 0 to 5 mph N | 1% |
| Saturday | 53°F | Partly Sunny | 0 to 5 mph W | 2% |
| Saturday Night | 36°F | Mostly Clear | 0 mph | 3% |
| Sunday | 59°F | Sunny | 0 to 5 mph W | 9% |
| Sunday Night | 36°F | Mostly Clear | 0 to 5 mph W | 3% |
| Monday | 63°F | Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 40°F | Mostly Clear | 5 mph W | 0% |
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 Nov 4, 2026.