Matt Noyes shares what’s in store for New England as we move through the month, including the chances of frost, snowfall, and the overall weather pattern and how that relates to precipitation and temperature here at home, and nationwide.
First Frost and Snowfall Chances
As we head into October, many of us start thinking about frost and snow. For higher elevations in Northern New England, including the Green Mountains, Great North Woods, and Northwestern Maine, the average first snow of at least a tenth of an inch typically occurs this month. For the rest of New England, most areas will see their first snowfall in November, while Cape Cod and coastal areas may not see snow until December.
In terms of frost, some locations like Concord, NH and North Adams, MA are already past due for their first frost of the season, although it hasn’t happened yet as of October 1st. Farther south, including Boston, the first frost usually doesn’t occur until early November.
October Weather Pattern: Split Jet Stream
The defining feature of the weather pattern for the first half of October is a split flow in the jet stream. This means that the northern jet stream, which brings disturbances, will be mostly moisture-starved, while the subtropical jet stream, which carries moisture, will stay separated to the south.
While these two streams can combine to create big storms, it’s unlikely we’ll see any significant storms for New England in the first half of the month. Instead, we’ll have quick-moving disturbances that bring scattered showers and bursts of cooler air. These bursts of cold air increase the likelihood of seeing our first frost in the next couple of weeks.
As we move further into the month, the split flow pattern will likely continue, meaning limited moisture for most of New England. The exception might be some areas in the Pacific Northwest and southeastern U.S., where recurring showers from the subtropical jet stream could tip the scale toward above-normal precipitation.
Temperatures and Precipitation
For most of New England, we expect October to be near or slightly above normal in terms of temperature. In Boston, the average high is 62°F, while the average low is 47-48°F. As for precipitation, it looks like we’re heading into a drier-than-normal period, with the exception of coastal Maine, which has been experiencing slightly higher rainfall.
While September ended up wetter than expected—thanks to Tropical Storm Helene—October’s pattern will be much different, with drier conditions dominating. This is good news for outdoor plans, but not so great for those hoping for much-needed rain to alleviate moderate drought conditions in parts of the region.
For New England, though, it looks like dry and cool weather will be the theme for October, with scattered showers possible as quick disturbances pass through.
Stay Connected with 1DegreeOutside
As we move through October, stay up to date with the latest weather changes by downloading the 1DegreeOutside Weather app. Get access to your 14-day forecast, hourly updates, and real-time radar for rain or snow. You can download it on the App Store or Google Play by searching Noyes’ One Degree Outside Weather.
