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Rensselaer, IN 47978 Weather
Current conditions
Observed at Valparaiso Porter County Municipal Airport · 22 min ago
Forecast
10-day-
Tonight
Clear, with a low around 43. Wind around 0 mph.
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Thursday
Sunny. High near 73, with temperatures falling to around 71 in the afternoon. North northeast wind 0 to 5 mph.
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Thursday Night
Mostly clear, with a low around 43. East northeast wind 0 to 5 mph.
National Weather Service forecast updated 5 hrs ago.
Hourly
Hourly forecast- Now53°
- 10 PM51°
- 11 PM49°
- Thu12 AM48°
- 1 AM47°
- 2 AM47°
- 3 AM46°
- 4 AM45°
- 5 AM44°
- 6 AM44°
- 7 AM44°
- 8 AM46°
- 9 AM52°
- 10 AM60°
- 11 AM65°
- 12 PM68°
- 1 PM71°
- 2 PM72°
- 3 PM72°
- 4 PM72°
- 5 PM71°
- 6 PM67°
- 7 PM62°
- 8 PM56°
10-day forecast
Details- TonightOct 21Clear43°
- ThuOct 22Sunny43°73°
- FriOct 23Sunny45°72°
- SatOct 24Mostly Sunny45°72°
- SunOct 25Partly Sunny47°75°
- MonOct 26Partly Sunny46°73°
- TueOct 27Partly Sunny44°66°
- WedOct 28Partly Sunny66°
- ThuOct 29Partly cloudy36°60°
- FriOct 30Cloudy44°60°
Days after the National Weather Service's seven are MET Norway's outlook, a computer model with no forecaster's review.
Radar
Full mapWeather news near Rensselaer
More weather news-
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Air quality
Air quality is satisfactory, and air pollution poses little or no risk.
Lafayette, IN reporting area · 1 hr ago. Data from AirNow (EPA and its state, local and tribal partners); preliminary and subject to change.
Sun & moon
Almanac
MonthlyRensselaer Wwtp, records since 1900. Normals 1991–2020. Data from NOAA's Regional Climate Centers (ACIS).
Nearby
- Merrillville 58 km
- Valparaiso 53 km
- Crown Point 52 km
- Saint John 59 km
- Cedar Lake 50 km
- Lowell 42 km
- Lakes of the Four Seasons 47 km
- Winfield 48 km
- Monticello 40 km
- Watseka 58 km
- Georgetown 58 km
- Beecher 58 km
Forecasters' discussion
From the National Weather Service office in LOT, issued 3 hrs ago
Key Messages
- The dry and unseasonably mild weather will continue through the upcoming weekend.
Discussion
Issued at 136 PM CDT Wed Oct 21 2026
An anomalously strong mid-level ridge over the central CONUS will anchor omega blocking across much of North America over the next several days. Meanwhile, an elongated surface ridge extending from the Lower Mississippi River Valley to the Canadian Maritimes is in the processes of congealing with another expansive high pressure shifting toward the Upper Great Lakes. As a result, quiet weather with unseasonably warm conditions will continue through the upcoming weekend. As was observed the past few mornings, generally clear skies and light/calm winds should promote shallow fog across primarily interior northern Illinois late tonight through sunrise Thursday.
The blocking pattern will slowly break down early next week as the ridge flattens and a southwestern upper-level low begins to meander toward the central CONUS. A series of smaller troughs on the periphery of a developing longwave trough across the north Pacific and western Canada will eventually pick up the southwestern low. Consensus guidance suggests that the influence of the low on our area could occur as early as Monday night, but more likely Tuesday and Wednesday. Cooler and more seasonable conditions would accompany this system.
Kluber
Aviation
Issued at 641 PM CDT Wed Oct 21 2026
Main aviation forecast concern is the potential for patchy IFR/LIFR fog to develop mainly northwest of Chicago early Thursday morning.
Surface high pressure ridge has shifted east of the area across lower MI/IN early this evening. Light south-southwest surface winds at the terminals are expected to quickly become light/variable or just calm early this evening, though there may be a brief (1-hour)period of light east winds at ORD/MDW/GYY as a weak lake breeze decays. The pressure gradient will remain weak into Thursday, keeping winds light/variable through the morning before becoming light (5-6 kts) northeast and eventually east in the afternoon/evening.
Clear skies and light/calm winds tonight will allow for ideal radiative cooling conditions, allowing shallow fog to develop in spots once again. This appears most likely across southern WI/northeast IA and far northern/northwest IL KRFD) where surface dew points remained in the mid-upper 40s during peak mixing Wednesday afternoon. While guidance is not too aggressive with lower visibilities, have maintained a 2SM IFR tempo and MIFG in the KRFD TAF, and will monitor overnight for tactical lower vsbys. The drier low-level airmass to the southeast looks to be less conducive to fog development with southeastward extent. Have maintained a 3SM MIFG tempo at DPA, with VFR conditions for the other Chicago area terminals.
Ratzer
Lot Watches
IL...None. IN...None. LM...None.
Forecasts, observations and alerts in the United States come from the National Weather Service (NOAA); radar from NOAA's Multi-Radar Multi-Sensor system; satellite imagery from NASA's Global Imagery Browse Services (GIBS) and NOAA's GOES satellites; the map from the U.S. Geological Survey's National Map; air quality from AirNow (EPA and its partners); hurricane information from the National Hurricane Center; climate normals and records from NOAA's Regional Climate Centers (ACIS). Forecasts outside the United States and the UV index: MET Norway (CC BY 4.0); observations outside the U.S.: airport reports via NOAA's Aviation Weather Center. Place names: GeoNames (CC BY 4.0). Data are copied on a schedule and may lag the sources; for warnings that affect your safety, follow your local National Weather Service office and emergency officials. Weather news is drawn from the 4Search index and reflects what the press published. Terms of use.