St. John Valley weather for Aug. 14-20, 2024

Joseph E. Becker, Special to The County
3 months ago

3-Day Outlook: Wed. Aug. 14 – Fri. Aug. 16

A backdoor cold front will slide from New Brunswick into the region and dissipate over western Maine tonight. Extensive smoke aloft from Canadian wildfires will create hazy conditions over the St. John Valley today. The front will bring a chance of afternoon showers and isolated thunderstorms; however, smoke may suppress any thunderstorm activity. Highs in the mid-70s are currently anticipated. Tonight, mostly cloudy skies with a slight chance of precipitation are expected across the Saint John Valley with lows in the upper 50s.

For Thursday, a closed low over the Maritimes will slide westward producing some instability over the Valley with a chance of showers. Partly sunny skies are expected with highs in the middle 70s. Thursday night, partly cloudy skies and a slight chance of showers for the SJV with lows in the upper 50s.

Friday becomes mostly sunny with highs climbing into the lower 80s. It will be a bit more humid with dew points in the upper 50s/low 60s. Friday night features clear skies with lows in the upper 50s.

Daily Summary 

Wednesday: Partly sunny. Patchy fog this morning. Scattered showers with isolated thunderstorms this afternoon. Highs in the mid 70s. North winds around 5 mph. Chance of rain 50 percent.

Wednesday Night: Mostly cloudy. Isolated thunderstorms in the evening. Patchy fog after midnight. Lows in the mid 50s. Light and variable winds. Chance of precipitation 20 percent.

Thursday: Patchy fog in the morning. Mostly cloudy with a chance of showers. A slight chance of thunderstorms in the afternoon. Highs in the mid-70s. South winds around 5 mph. Chance of rain 50 percent.

Thursday Night: Partly cloudy. A chance of showers with a slight chance of thunderstorms in the evening. Lows in the mid-50s. South winds around 5 mph. Chance of rain 40 percent.

Friday: Partly sunny in the morning, then mostly sunny with isolated showers in the afternoon. Highs in the upper 70s. South winds around 5 mph. Chance of rain 20 percent.

Friday Night: Mostly clear. Lows in the upper 50s.


4-7 Day Outlook: Sat. Aug. 17 – Tue. Aug. 20

An upper-level trough over the Great Lakes along with a surface low and fronts over the Ohio Valley will gradually approach over the weekend into early next week. Currently, mostly sunny skies are expected Saturday with a slight chance of afternoon/evening thunderstorms. A chance of thunderstorms and isolated thunderstorms overnight with a chance of showers and isolated afternoon thunderstorms Sunday and Sunday night. 

Showers, especially Monday afternoon, along with isolated thunder is also possible Monday as the low and fronts move across the state. A cold front looks to move through from the west/northwest Tuesday into Wednesday with showers, mainly in the afternoon, and isolated thunderstorms once again. Tropical Storm Ernesto tracks by well-offshore based on most forecast model consensus early next week.

Daily Summary

Saturday: Partly sunny. Scattered showers in the afternoon. Highs in the upper 70s. Chance of rain 40 percent.

Saturday Night: Mostly cloudy with scattered showers. Lows around 60. Chance of rain 50 percent.

Sunday: Mostly cloudy with scattered showers. Highs in the mid-70s. Chance of rain 50 percent.

Sunday Night: Mostly cloudy with scattered showers. Lows around 60. Chance of rain 50 percent.

Monday: Mostly cloudy. Scattered showers in the morning, then numerous showers in the afternoon. Highs in the mid 70s. Chance of rain 60 percent.

Monday Night: Mostly cloudy. Numerous showers, mainly in the evening. Lows in the upper 50s. Chance of rain 60 percent.

Tuesday: Partly sunny with scattered showers in the morning, then mostly cloudy with numerous showers in the afternoon. Highs in the lower 70s. Chance of rain 60 percent.

Tuesday Night: A chance of showers. Partly cloudy, with lows in the mid-50s. Chance of precipitation is 30 percent.

8-14 Day Regional Climate Tends: Wed. Aug. 21 – Tue. Aug. 27 

Above normal temperatures / Above normal precipitation

Note: Computer model precision diminishes the further into the week the forecast projects. Check The County.me or the National Weather Service Caribou, ME at for weather updates with more current information for the Saint John Valley.

The Week Ahead is the work of UMFK Professor Joseph E. Becker based on personal weather station data, various computer forecast models, and information that the National Weather Service, NOAA, and other weather resources provide.