Mountainside, NJ Weather Tomorrow

See tomorrow's forecast for Mountainside together with a reliable 5 day outlook featuring daily precipitation forecasts, changing sky conditions, daytime highs, overnight lows, Fahrenheit and Celsius temperatures, sunrise, sunset, wind chill, and local wind details for the Mountainside area and around Union county, New Jersey.
Updated: Thu Nov 12th 2026 12:00 AM EST
Mountainside, NJ Weather – 11-12 – Overcast
58° / 48°
Overcast
Daytime highs will reach 58°F with lows dropping to 48°F in Mountainside, where it will be overcast. The chance of rain is 89% with an estimated 0.81in. Wind will be moderate, blowing around 11mph on average and gusts of 20.5mph at 11 PM. High humidity with average of 83% is anticipated, the maximum being 92% at 2 PM and 69% being its lowest at 1 AM. Barometric pressure is its highest of 29.76inHg at 1 AM, a lowest point of 29.41inHg at 4 PM with an avg 29.54inHg.
Mountainside, NJ Weather – 11-13 – Light Drizzle
47° / 40°

Weather Tomorrow

Light Drizzle
Mountainside is set for light Drizzle with temperatures peaking at 47°F and dipping to 40°F. The chance of rain is 90% with an estimated 0.37in. Wind will be moderate, blowing around 13mph on average and gusts of 24.1mph at 4 AM. High humidity with average of 87% is anticipated, the maximum being 94% at 11 AM and 73% being its lowest at 11 PM. Barometric pressure is its highest of 29.74inHg at 10 PM, a lowest point of 29.44inHg at 12 AM with an avg 29.59inHg.
Mountainside, NJ Weather – 11-14 – Partly Cloudy
46° / 36°
Partly Cloudy
Mountainside could see cloudy skies with daytime highs of 46°F and nighttime lows near 36°F. There's a very small chance of rainfall, only about 8%. Wind will be moderate, blowing around 11mph on average and gusts of 19.8mph at 1 PM. The humidity will be on the higher side, averaging about 62%, the maximum being 74% at 7 AM and 46% being its lowest at 1 PM. Barometric pressure is its highest of 29.98inHg at 11 PM, a lowest point of 29.74inHg at 12 AM with an avg 29.84inHg.
Mountainside, NJ Weather – 11-15 – Partly Cloudy
47° / 37°
Partly Cloudy
Daytime highs will reach 47°F with lows dropping to 37°F in Mountainside, where it will be cloudy. There's a very small chance of rainfall, only about 8%. Wind will be moderate, blowing around 13mph on average and gusts of 22.7mph at 7 AM. The humidity will be on the higher side, averaging about 64%, the maximum being 76% at 7 AM and 51% being its lowest at 2 PM. Barometric pressure is its highest of 30.27inHg at 10 PM, a lowest point of 29.99inHg at 12 AM with an avg 30.12inHg.
Mountainside, NJ Weather – 11-16 – Partly Cloudy
49° / 40°
Partly Cloudy
In Mountainside, cloudy skies are likely with a high near 49°F and a low around 40°F. There's a very small chance of rainfall, only about 7%. Winds will be light at 9mph and gusts of 19.3mph at 7 AM. The humidity will be on the higher side, averaging about 66%, the maximum being 75% at 7 AM and 51% being its lowest at 1 PM. Barometric pressure is its highest of 30.43inHg at 7 PM, a lowest point of 30.28inHg at 12 AM with an avg 30.37inHg.
Mountainside, NJ Weather – 11-17 – Sunny
52° / 37°
Sunny
Highs will reach 52°F with lows near 37°F in Mountainside, where a sunny day is. There's a very small chance of rainfall, only about 6%. Winds will be light at 5mph and gusts of 14.3mph at 1 AM. The humidity will be on the higher side, averaging about 68%, the maximum being 81% at 7 AM and 49% being its lowest at 1 PM. Barometric pressure is its highest of 30.46inHg at 7 AM, a lowest point of 30.41inHg at 1 PM with an avg 30.43inHg.

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