Weekly weather forecast July 11–18

A bit of a weather rollercoaster sets up over Waltham this week. The forecast begins with clouds, fog, and locally heavy downpours as a slow-moving front lingers over the area. Conditions gradually improve by the weekend, with dry weather, brightening skies, and seasonable warmth.

Then, from Monday through midweek, summer arrives in full force. A southwest flow brings rising temperatures and muggy air, with highs soaring into the upper 80s and low 90s. A few scattered afternoon thunderstorms are possible, but most days will be dominated by heat, humidity, and hazy sunshine—a full return to peak summer conditions across the region.