Apex Wx

via Google Translate

7-Day Outlook: Mon. July 13 – Sun. July 19, 2026

A weak trough of low pressure will move across the Saint John Valley today, bringing mostly cloudy skies along with a chance of showers and isolated thunderstorms during the afternoon and early evening. Southwest winds will average around 5 to 10 mph. Afternoon temperatures will reach the upper 70s to around 80 degrees.

Any remaining showers or thunderstorms will diminish during the evening, leaving mostly to partly cloudy skies overnight. Winds will become light and variable, with overnight lows settling into the lower 60s.

Attention then turns to Tuesday, when a warm and increasingly humid air mass will overspread the region ahead of a strong cold front approaching from the west. While much of the day may be dry, several disturbances moving through the atmosphere could trigger rounds of thunderstorms, with one round possible during the morning across northern Maine and a second, potentially stronger round developing during the late afternoon and evening. The exact timing and location of the storms remain somewhat uncertain.

Northern Aroostook County remains within an area of enhanced risk for severe thunderstorms on Tuesday (Level 3 of 5 on the Storm Prediction Center's scale). The primary threat will be damaging wind gusts of 60 to 70 mph, although a well-organized line of storms could produce locally stronger, hurricane-force wind gusts. Large hail up to around 2 inches in diameter will also be possible, and an isolated tornado cannot be ruled out if individual thunderstorms develop ahead of the main line. If earlier storms do not significantly stabilize the atmosphere, strong to severe thunderstorms could continue into Tuesday night as the cold front moves through the region.

In addition to the severe weather threat, Tuesday will be the hottest and most humid day of the week. Afternoon temperatures will climb into the mid-80s, while increasing humidity will make conditions feel even warmer. Southwest winds will average 5 to 15 mph, with higher gusts possible outside of thunderstorms.

The cold front will move east of the region Tuesday night, with showers and thunderstorms ending from west to east overnight. Skies will gradually become partly cloudy, and winds will shift to the west as cooler and less humid air begins to arrive. Overnight lows will fall into the lower 60s.

Wednesday will be noticeably cooler and much more comfortable behind the cold front. Mostly sunny skies are expected for much of the day, although a few afternoon showers or thunderstorms cannot be ruled out as cooler air moves across the region. West winds of 10 to 20 mph, with higher gusts, will make it feel less humid. Afternoon temperatures will reach the mid-to-upper 70s, with overnight lows Wednesday night falling into the mid-50s under partly cloudy skies.

Another cold front will move across the Saint John Valley on Thursday, bringing a chance of scattered afternoon showers and isolated thunderstorms. While many locations will remain dry, a few showers and thunderstorms may develop during the afternoon before diminishing during the evening. West winds will average 10 to 15 mph, with gusts of 20 to 25 mph, making for a breezy day. Afternoon temperatures will remain cooler than earlier in the week, reaching the upper 60s to around 70 degrees.

Any lingering showers or thunderstorms will end Thursday evening, followed by partly cloudy skies overnight. Cooler, drier air will settle into the region, with overnight lows dropping into the upper 40s to lower 50s.

High pressure building south from the Hudson Bay region will bring a stretch of pleasant summer weather for Friday and Saturday. Expect mostly sunny to sunny skies, comfortable humidity levels, and seasonable temperatures. Afternoon highs will range from the lower 70s on Friday to the mid-70s on Saturday, while overnight lows will remain in the lower 50s under partly cloudy skies.

By late Saturday night into Sunday, a weak trough moving across Maine will bring an increasing chance of scattered showers to the Valley. Although much of Sunday will feature a mix of clouds and sunshine, a few showers may develop during the day and continue into Sunday night. Afternoon temperatures will remain in the mid-70s, with overnight lows Sunday night settling into the middle 50s.

Updated every 3-6 hours from NWS Caribou

Weather Notice: This information is based on available computer models and data and may not reflect current conditions or later forecast updates. Always visit NWS Caribou at https://www.weather.gov/car/ for the latest official watches, warnings, and advisories for northern Maine.

Credits

• Sun/Moon data from US Naval Observatory with additional information from timeanddate.com.
• NOAA Warning Banner provided by WillyWeather.com.
• Until Dec. 2026, additional Archived Weather Data from Apex Wx is at the University of Utah's MesoWest
• Apex Wx logo by Joanna Becker ©2016 (Visit Bushi and Brush Arts Dojo)

How accurate are forecasts? On average, for the first 72 hours the accuracy is 90 percent. For days 4-7 it is 70 percent. After seven days, it is 50 percent—just good for indicating trends. On social media and other similar sites, posts that show a forecast model run a week out are just for clicks and likes, and are not considered reliable. Extended forecasts are subject to change as weather patterns evolve, so should be considered guidance rather than precise predictions. Check for updated forecasts and advisories as conditions develop.