October forecast

Higher-than-normal temperatures are forecast in the Northeast for much of the first half of October. (Climate Prediction Center / September 30, 2013)

The calendar says fall is here, but temperatures are forecast to bounce back closer to the norm for late August than for early October this week.

Highs are forecast in the lower 80s through the week, with lows around 60 degrees. By this time of year, it's more common to see highs in the upper 60s, with average lows dropping into the 40s.

Dew points are forecast in the 50s up into the lower 60s, meaning humidity will be well below August's oppressive levels, but the air won't be quite as crisp as it has been in recent weeks.

A jet stream pattern providing a southwesterly flow of air is responsible, according to AccuWeather.com.

Climate forecasts show the pattern could continue for the first half of the month. Forecast maps show at least a 50 percent chance of warmer-than-normal temperatures for Maryland and the mid-Atlantic, with an even greater likelihood for unseasonable warmth in New England.

The weather will be somewhat of a turn from a spell of seasonable fall weather in the second half of September. The month will end Monday with average temperatures right on the norm, at 67.9 degrees through Sunday just a tenth of a degree below average.

For the first half of the month, highs hovered in the 80s and 90s, but Sept. 14 began a more than two week stretch with highs in the 60s and 70s -- a streak of below-80-degree weather likely to snap Tuesday.