Merrillville, IN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Merrillville, a town in Lake County, Indiana.
This Afternoon
66°F
Slight Chance Rain Showers
A slight chance of rain showers and a slight chance of drizzle. Cloudy. High near 66, with temperatures falling to around 58 in the afternoon. West southwest wind around 15 mph, with gusts as high as 25 mph.
7-day forecast for Merrillville
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 66°F | Slight Chance Rain Showers | 15 mph WSW | 2% |
| Tonight | 47°F | Slight Chance Rain Showers then Slight Chance Rain | 10 to 15 mph SW | 17% |
| Thursday | 54°F | Mostly Cloudy then Chance Rain | 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) for Merrillville (41.473, -87.318). Updated through the day.
Growing snapshot for Merrillville
Last spring frost
Apr 22
First fall frost
Oct 25
Growing season
185 days
Hardiness zone
6a
More local growing data for Merrillville: nearby ZIP 46410 weather · frost dates · planting calendar · Indiana frost dates
Nearby towns & communities
Cedar Lake
Crown Point
Dyer
East Chicago
Gary
Griffith
Hammond
Highland
Hobart
Lake Dalecarlia
Lake Station
Leroy
Lowell
Munster
New Chicago
Ross
Schererville
Schneider
Shelby
St. John
Whiting
Winfield
Climate data from the nearest NOAA station, Valparaiso Wtr Wks, In (15.5 mi from Merrillville). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.