77 degrees Friday: October heat spike ahead for region

Residents in the Philadelphia region can expect a brief period of mild weather before temperatures climb sharply late this week. Tuesday brings a high of 66 degrees, marking a slightly warmer start to the day. The primary change for residents this week is not rain, but the return of heat. A persistent ridge of high pressure has dominated the area for more than a week. That pattern is expected to hold through much of the upcoming seven days.

The weather model shows a broad upper-level ridge building across the central and eastern United States. This system keeps high pressure in control, limiting opportunities for rain. Winds will remain light, and skies will stay mostly clear. The next significant rainfall event is not expected to arrive this week.

Temperatures will begin rising on Thursday as the ridge strengthens. Warmer air will spread into the northeast, driving highs to the lower 70s. The peak of this warm spell arrives on Friday. High temperatures are forecast to reach the mid to upper 70s, specifically 77 degrees. That figure is more than 10 degrees above the average for the end of October. Despite the heat, humidity should remain comfortable, allowing for cooler nights. Overnight lows will stay in the 50s, dropping to 45 degrees on Wednesday.

The weather pattern continues into the weekend. Saturday, Halloween, looks like a mix of sunshine and clouds with no significant rain. Temperatures will hover in the lower to mid 70s. Trick-or-treaters can expect comfortable conditions in the 60s during the early evening. Sunday will be a bit cloudier but still mild, with a high near 70 degrees. The dry spell appears likely to continue right through the holiday, with no severe weather threats on the horizon.

A weak cold front brings a modest cooldown on Tuesday and Wednesday. This temporary dip in temperature precedes the warmer air arriving later in the week. The extended dry stretch is the main story for the region. Sunshine and light winds characterize the forecast. The combination of dry air and clear skies allows temperatures to cool off efficiently overnight, even on the warmer days. The weather holds steady through the weekend, providing a mild finish to October before a chance of showers arrives on Monday.

The forecast indicates a high of 66 and a low of 52 on Tuesday. Wednesday follows with a high of 67 and a low of 45. Thursday sees a high of 72 and a low of 49. Friday peaks at 77 with a low of 52. Saturday brings a high of 70 and a low of 51. Sunday mirrors Monday with highs near 72 and lows around 51. The final day of the forecast, Monday, includes a chance of showers with a high of 72 and a low of 61.