Merrillville, IN Weather & Growing Conditions
This Afternoon
66°F
Slight Chance Rain Showers
A slight chance of rain showers. Cloudy. High near 66, with temperatures falling to around 57 in the afternoon. West southwest wind around 15 mph, with gusts as high as 25 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 66°F | Slight Chance Rain Showers | 15 mph WSW | 5% |
| Tonight | 49°F | Patchy Drizzle | 10 to 15 mph SW | 18% |
| Thursday | 53°F | Cloudy then Chance Rain Showers | 10 to 15 mph WSW | 43% |
| Thursday Night | 40°F | Rain | 10 mph NW | 81% |
| Friday | 49°F | Slight Chance Rain | 10 to 15 mph NNW | 24% |
| Friday Night | 36°F | Mostly Cloudy | 5 to 10 mph NNW | 8% |
| Saturday | 50°F | Mostly Sunny | 5 mph NW | 3% |
| Saturday Night | 33°F | Mostly Clear | 0 to 5 mph W | 0% |
| Sunday | 56°F | Sunny | 5 to 10 mph W | 1% |
| Sunday Night | 35°F | Mostly Clear | 0 to 5 mph W | 0% |
| Monday | 60°F | Sunny | 0 to 10 mph SW | 0% |
| Monday Night | 40°F | Mostly Clear | 5 mph SW | 0% |
| Tuesday | 61°F | Sunny | 5 mph W | 1% |
| Tuesday Night | 38°F | Partly Cloudy | 0 mph | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Merrillville, IN
Last spring frost
Apr 22
First fall frost
Oct 25
Growing season
185 days
Hardiness zone
6a
Explore more for Merrillville, IN: full frost dates · planting calendar · Indiana frost dates
Climate data from the nearest NOAA station, Valparaiso Wtr Wks, In (15.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 5, 2026.