Matthew Moll

Friday, Dec. 19 – Widespread rain and strong winds followed by a sharp cold frontal passage 

A high-impact weather day. Periods of rain overspread the area before dawn and continue through the morning, occasionally heavy, especially early. Strong south winds gust 40–45 mph before shifting west during the afternoon as a powerful cold front moves through. Rain tapers by mid to late afternoon, followed by rapidly falling temperatures, clearing skies, and blustery west winds Friday night.   ● High: 56 to 58°F (early) | Low: 25 to 27°F | Wind: South 15 to 20 mph with gusts 40–45 mph; shifting west and remaining gusty overnight  ● Sky: Cloudy with rain early, clearing late  ● Chance of precipitation: 100 percent

Thursday, Dec. 18 – Dry, noticeably milder, and calm before an overnight storm arrival 

A quiet and seasonably mild December day with light winds and abundant sunshine early, followed by increasing high clouds late in the day as a strong storm system approaches from the west. Conditions remain dry through the evening, but rain spreads into Waltham after midnight as winds begin to increase from the south overnight.  ● High: 48 to 50°F | Low: 38 to 40°F | Wind: Calm becoming south 5 to 10 mph overnight, gusts up to 30 mph late ● Sky: Mostly sunny early, becoming cloudy overnight ● Chance of precipitation: 80 percent late night

Waltham Weather Outlook: Dec. 17 to Dec. 24, 2025 

Wednesday, Dec. 17 – Cold and quiet 

Mostly sunny with highs near 30. Dry conditions persist as the cold pattern continues. ● High: Near 30°F | Low: Upper teens ● Chance of precipitation: 0 percent

Tuesday, Dec. 16 – Mostly sunny, cold, slightly milder 

Dry and quiet with highs near 30. Another cold night follows under clear skies. ● High: 29 to 31°F | Low: 16 to 18°F | Wind: West around 7 mph ● Sky: Mostly sunny ● Chance of precipitation: 0 percent

Monday, Dec. 15 – Bright, dry, and very cold 

Arctic high pressure brings sunshine but very cold temperatures. Highs only in the mid-20s. Light northwest winds keep wind chills in the teens.  ● High: 25 to 27°F | Low: 12 to 14°F | Wind: Northwest around 7 mph ● Sky: Mostly sunny ● Chance of precipitation: 0 percent

Sunday, Dec. 14 – Partly sunny, cold, slight morning snow chance; overnight very cold with increasing northwest winds 

A slight chance of morning light snow depending on the coastal system’s exact track. Most of the day is dry with partly sunny skies. Temperatures remain cold and may fall during the afternoon as another arctic front arrives. Overnight a reinforcing arctic front sweeps through, bringing clearing skies, falling temperatures, and increasing northwest winds. Wind chills drop into the single digits. Skies remain mostly clear overnight with no precipitation expected.  ● High: 30 to 32°F | Low: 15 to 17°F, overnight 14 to 17°F | Wind: West 6 to 9 mph, gusts to 20 mph; overnight northwest 10 to 15 mph, gusts 20–25 mph ● Sky: Partly sunny; overnight mostly clear ● Chance of snow: 20 to 30 percent early; overnight 0 percent

Saturday, Dec. 13 – Partly sunny, cold, clouds increase at night; overnight lower snow risk

A quieter but still cold day. Highs reach the mid-30s under partial sun. Winds are light. Clouds increase at night as a coastal system passes well south. Overnight, recent model trends favor a more southern storm track, reducing the chance for accumulating snow. However, this remains not set in stone. Any northward jog could still bring a period of light snow toward daybreak Sunday. ● High: 34 to 36°F | Low: 23 to 25°F | Wind: Southwest 5 to 7 mph ● Sky: Partly sunny, turning mostly cloudy at night ● Chance of precipitation: 0 percent during the day

Friday, Dec. 12 – Cold, sunny, and blustery 

A bright but cold day with highs only near the low-30s. Winds remain gusty early but diminish slowly through the afternoon. Dry conditions prevail.  ● High: 31 to 33°F | Low: Around 21°F | Wind: West 14 to 18 mph, gusts to 30 mph ● Sky: Sunny ● Chance of precipitation: 0 percent

Thursday, Dec. 11 – Windy, sharply colder, isolated flurries; evening has biting wind chills 

A cold, blustery day behind the front. Temperatures fall through the 30s and hover near or below freezing for much of the afternoon. Strong west winds gust 35–45 mph. A stray flurry or brief snow shower is possible but most of the day is dry with sun and fast-moving clouds. The evening is partly cloudy, windy, and cold. West winds continue to gust 35–45 mph early. Wind chills fall to between 0 and 10°F, occasionally lower on exposed hilltops.  ● High: 34 to 36°F (early), falling thereafter | Low: Around 21°F | Wind: West 20 to 25 mph, gusts 40–45 mph ● Sky: Mostly sunny with scattered clouds, isolated flurries; overnight, partly cloudy ● Chance of precipitation: 20 percent; overnight 10 percent (brief flurry possible)